My gameplay says otherwise.
Apart from that, here, all the tactics in the game. Some of them are quite empty like my soul
I'm aware. That's how I know there are separate tactics that trigger but look almost the same as each other. As for the AI charging for no reason, I've not had that same experience and there is nothing in there (that I've found yet) to make them just switch tactics without something effecting the power calculation.
edit: I will say that you can make AI archers do some pretty dumb things just by positioning yourself oddly away from your troops but not actually force them to charge.