Brain of Cthulhu
The Tsunami isn't versatile? Ranger is the most versatile class in the entire game, almost every one of its weapons can be used with different kinds of ammo for different situations, and some gain extra effects with Endless Quiver and Endless Musket Pouch. Imagine you're using any bow or repeater, it doesn't have to be Tsunami. Want a good option for lined-up crowds? Use Jester's Arrows. Want decent DPS and a DoT effect against bosses? Use Frostburn or Venom Arrows. Want to annihilate events and enemies underground with smart-bouncing projectiles? Use Chlorophyte Arrows. Want to deal absurd DPS against anything that doesn't move around too much? Use Holy Arrows. Want to apply a powerful debuff that also boosts your other weapons? Use Ichor Arrows. Want to reliably hit targets at long range and potentially save an accessory slot, as well as inflicting a debuff? Use Ichor or Venom Arrows. Want to deal large amounts of knockback and keep enemies off you? Use Hellfire Arrows. Want to endlessly spam projectiles? Use the Endless Quiver.There are only a couple things that Terra Blade will actually shred: Golem and invasions. Against bosses like Duke, Empress and Moon Lord, hitting Terra Blade with the actual blade (which if where most of its DPS comes from with whip boosts in mind) isn't really practical. The beam, while good, still has overall on par or less DPS than Blade/Sanguine, even though Terra Blade is a post-Plantera weapon. Tsunami/Eventide are great, but are weapons that you'd usually obtain post-Plantera or post-Golem (eventide especially) that arguably get replaced by Phantasm soon after at that point. Tsunami can be obtained Pre-mech, but doing so isn't exactly easy, and even then it doesn't attack mobs automatically & effectively protect you like Blade/Sanguine does, it's not a super versatile weapon that all classes can use for support, and even then once Kaleidoscope is obtained Tsunami's DPS isn't all that much higher than Blade Staff's. Not to mention the defensive benefits of using Blade Staff. Tsunami has higher damage, but it's significantly more difficult to obtain Pre-mech, and it doesn't have the insane utility & versatility that Blade/Sanguine have. Same applies to Razorblade Typhoon, except it overall deals less damage than Tsunami (unless Destroyer) but is way better than it against crowds. The fact that these two Pre-mech weapons (mainly Blade) can actually compete with these weapons that are post-Golem or post-Cultist in term of power is really telling. Oh yeah, and if you're going to use Razorblade Typhoon, you can use both it and Sanguine effectively with Forbidden Armor.
"They have quite a bit of damage" is an understatement. Going with Expert & "standard" gears, Sanguine + Firecracker kills Destroyer in 48 seconds, kills Twins in a minute flat and kills Prime in 54 seconds. Against Plantera, both Blade & Sanguine with their appropriate whips kill Plantera in under 30 seconds. With a full warding build with Hallowed Armor, Blade Staff kills Plantera in only 31 seconds. And against EoL, with Hallowed Armor, Blade Staff can do it in a little over 40 seconds with Durendal or Betsy's Wrath. Tiger needs the Desert Key, and a Summoner player is unlikely to get that without grinding because Desert & Underground desert offer little for Summoners unless they go for Forbidden Armor. And even then, Tiger can struggle to hit flying enemies consistently. Ravens in general are pretty slow and not as reliable, even if their actual DPS is very high. Xeno Staff is post-Golem and it's honestly better to just kill cultist and get Cells/Dragon unless you think that strategy is cheap and boring (like I do, actually).
Blade & especially Sanguine have more than enough range with their AI. Unless your strategy is to just run away as far as possible from the boss, their supposed "limited" range is almost never an issue. Both Blade & Sanguine are Pre-mech and easily last all the way to Post-golem or post-cultist depending on if you want to get Xeno Staff and/or fight EoL before cultist. I don't know what "LoS", I assume it means something related to "Sight" and detecting enemies? If that's the case then that's really not an issue either. Blade will react and attack enemies instantly, especially. They can simply be treated as weapons that don't attack through walls. Needing to min max build? I don't see how, and I don't see why this would apply to them and not other weapons. Blade thrives with defensive builds that neglect % boosts, and it also has a home with Titanium Armor. Sanguine is a great support for any character period, but especially Forbidden Armor.
There's a noticeable margin in the usefulness of Blade/Sanguine to other weapons. They are available earlier than Terra Blade and by default lasts longer & contributes more in the long run. They are easier to obtain than Razorblade/Tsunami. They, once again, have way more versatility and utility compared to those weapons. And even then, against daytime EoL, Blade is scarily close to rivaling said weapons, especially with the fact Hallowed Armor is preferrable for Daytime EoL. With Dart Gun/Rifle in mind it's not even a contest, Blade/Sanguine deal on par or better damage against bosses while being better at arguably everything else & having more longevity. Just look at Qwerty's EoL kill times for example: Dart Rifle took 87 seconds to kill EoL, while Blade takes around half that time to kill EoL. That's what I mean by longevity. If anything, the longevity of Dart Gun/Rifle is overrated. Either Dart Gun/Rifle just aren't as good as people think (especially with the nerf now in effect), or Blade/Sanguine (at least Blade) are indeed SS tier. No matter which character you're playing as, Pre-mech mainly you're missing out by not having Blade or Sanguine as a support minion. Even at their most minor role, they make a noticeably difference in making your character stronger. Not just some crappy grounded minion that barely does anything at all: Sanguine actively contributes and increases your overall DPS by an actually significant amount, while Blade offers amazing protection against Underground & Hardmode Dungeon enemies.
I don't have experience with Pirate invasion, and while Crystal/Cursed Darts are definitely safer, they still take longer to kill crowds. Especially Pirate Captains. What I had in mind primarily was underground & dungeon enemies.
Drop off isn't a significant issue. Blade Staff switches targets instantaneously, especially combined with how fast it attacks, while Sanguine can easily hit multiple targets. And simply hitting with whips will stunlock groups of enemies because of their big hitboxes. Also, "Firecracker can only be applied to 1 enemy per swing" is a no-issue because again Sanguine easily shreds crowd of enemies, especially if you take advantage of right click to make them target enemies at the far back. And even then the damage & large hitboxes provided by whips is more than enough, especially if you have Obsidian Armor.
How would I deal with that? Simple. I let the two enemies fall on me, Blade Staff instantly responds and keeps the enemy airbone while I kill them with whips. Any Dungeon Spirits that may spawn will be instantly stunlocked as well, zero risks. I then let the Paladin approach me from above, and I simply stunlock and kill it with Whips & Blade with ease. It's actually faster and better to engage the enemies by letting them fall on me and letting Blade Staff do its job, than "playing it safe" with Crystal darts which once again deal subpar single-target damage.
The Diabolists and other teleporting Dungeon enemies? Don't worry about them at all. You're greatly underestimating these little daggers.
How come you're saying that the Blade Staff and Sanguine Staff's range isn't an issue when earlier you were saying that if you attack bosses as a ranger they're going to lose aggro and stop attacking?
Why is performance against a Post-Plantera boss the only evidence that pre-mech bosses weapons are better than some other pre-mech bosses weapons? Test them all individually with a pure class build for each weapon, against Queen Slime and the mech bosses.
Desert Tiger Staff does not struggle with hitting flying enemies. As of 18.104.22.168, the Tiger can bounce above flying enemies, mostly staying in the same spot relative the target, dealing consistent damage. And don't call it "crappy grounded minion that can barely do anything at all"!
LoS means line of sight, which both Blade Staff and Sanguine Staff need in order to actively attack enemies.
In that Hardmode Dungeon scenario, would the Paladin just stand there, patiently waiting until you finish off the other two enemies before it attacks? No! If you go around the corner and start attacking the weaker enemies, the Paladin will almost immediately start throwing hammers at you, which you won't be able to dodge in the small space that you'd be in. The hammers hit very hard and at fired at a rapid rate, so you'd be killed very quickly.
Also keep in mind that the method of obtaining a weapon isn't factored into its rank, this tier list is about performance.