Hmmm...
Why are you trying to introduce a new item drop from King Slime when you could just make it require the slime blocks you make from the Solidifier?
Since the sprite you've made has a crown on it, how about...
Headpiece: Gold/Platinum Crown + 20 Slime Blocks + 5 Pink Slime Blocks
Chest piece: 1 Ruby + 35 Slime Blocks + 15 Pink slime blocks
Leg piece: 1 Ruby + 25 Slime Blocks + 10 Pink Slime Blocks
So in total, you'd need 3 rubies, 5 gold bars, 80 Gel, and 30 Pink Gel.
Since you need the solidifier to craft these pieces, it keeps it so you need to beat the King at least once to craft it, which is pretty difficult with only a single 8-damage baby slime.
Now, as for the stats...
Summoners have the lowest defense. This set shouldn't have very much armor (At least, not the Normal Slime Armor. Royal Slime Armor can keep the 10 Defense.) or else it will completely over-shadow the Bee Armor, instead of being a side-grade at best. (Trading a minion for more armor and general minon %damage). I'd suggest halving it to 5 or less, especially since it gives you 4 total minions. I've seen how crazy powered-up baby slimes can get. They're insane! The EoW didn't stand a chance against them, ha ha. One thing to note: Because of how low the damage of baby slimes is, the 15% damage bonus equates to about... +1 damage. :v Perhaps the bonus should be "Slime minions do +3 damage". The Slime mount can keep the +15%, since it does about 40 already, so the +15% would help it nicely.