Buffs don’t stack is what’s stopping things. You can have a few bonuses, but you’ll only ever take the best of those types. So you can have an item bonus, a status bonus, and a circumstance bonus.

Item bonuses are pretty straightforward.

Status bonuses are typically from spells, so Guidance, Athletic Rush, etc.

Circumstance bonuses are a little harder to pin down because they can be finicky and decided by the GM. But it’s typically an environmental effect. Strong winds at your back give you a +2 circumstance bonus to Tumble Through maybe.

So say you have a striking rune, Guidance, and a circumstance bonus to give you more, that’s generally looking at +1+1+2. So that is very good, having a +4 to hit.

But honestly, Pathfinder is built for tactics like that and encourages them. Flanking, frightened, slowed, sickened, prone, off-guard, etc. All of the penalties you can stack on an enemy are there for a reason, and being able to take advantage of that tactically is all part of the game. Assuming you have a good GM.

So yeah, make a party of bard bard bard fighter and see where it gets you. I guarantee it’s not optimal, but it’d be fun.