Who said there is no post golem versions for each class? Old One's Army armor is very overlooked by most of the player base. They provide a ridiculous amount of raw stats in exchange for a less class-focused set bonus and, especially in the case of rangers, losing its special set bonus doesn't really practically affects it (since shroomite's set bonus is kind of useless in single player). Their 60% extra minion damage and boost to its respective sentry is also really nice (especially for events where any 5 boosted sentries shred pretty much every grounded enemy in the celestial pillars).
Ironically, the only case where it is somewhat worse than its counterpart is mage, or dark artist's armor. The stats are fine but it just doesn't compete against the unconditional extra damage provided by spectre mask and healing of spectre hood, not to mention that flame burst is also quite weak compared to the other OOA sentries.