Is a sentry focused summoner viable in terraria?

the extra sentry slots mostly come from the Old One's Army armour sets the Tavernkeep sells, Squire, Monk, Huntress and Apprentice. that's what makes a sentry build actually feel like one. before hardmode it's honestly a rough ride.

It works, it's just harder than the normal minion setup. Sentries don't move, and most boss fights drag you all over the place, so you keep leaving them behind. You also start with only one sentry slot. What works is a hybrid: minions doing damage while you move, sentries dropped where the fight actually happens, and gear that adds sentry slots. Build an arena for bosses, sentries love a fixed spot. The Tavernkeep's sentries and the Queen Spider staff in early hardmode are where it starts feeling good.