Are bayonet techs critical in early game?

[Slaists]

I've seen it mentioned frequently that bayonet techs are one of the first things one should research in the game. I disagree. Probably the most critical early game military tech is square formation. The way it is built in the game, square formation's bonuses allow line infantry to hold their own against cavalry even without any bayonets (try it out). So, after the square formation, my early research shifts to either the industrial or enlightenment side of the tree.

For bayonets: I either buy or steal them from the AI or just wait until their research time is down to 1 to 2 turns (as you develop your university up, put more gentlemen in).