The AI could definitely improve on its use of archers. I think it has improved somewhat with its javelin skirmishers though. I find myself having skirmisher duals much more, and the AI typically sends some infantry ahead of its skirmishers which makes my own skirmishers retreat, giving its own ones a chance to launch an uncontested volley of pointy spears. Hence I return the favour by sending my own infantry or cavalry forward to force their's back again. I've had a few battles now where much of the opening action in the battle is a series of skirmishing and pre-emptitive charges by both sides, and the main fight doesn't occur until most of the missiles are spent. The AI definitely seems more organised than before, though its still restricted by tight formation issues and there's not enough pro-activeness about it.

The AI is now basically at the level I'd expect it to be when the game was first released.