I have only been playing WE for a short while, and so far I haven't been able to fight any really "grand" battles. Hordes don't form as often as before and with a good general (rank 4 is sufficient) and teched-uped troops, I can easily defeat 1000+ troops with, say only 400 - 500 and slaughter most of them.

I did ran into reinforcement from the AI a couple of times, where they came from diffrent spots but I was able to divide and conquer with my very tired troops.

As far as archer's concern, I find them really really bad at melee, thus their charge doesn't really make much of a diffrence. And your archers might suffer atrocious casualty. Once I had some hard time fighting monks and decided to charge my archers over. I won the battle, but the log file showed that that one single monk unit(60) was able to kill about 120 of my men, most of them being the poor archers.

To answer you question, I don't withdraw, and I don't want to charge the archers either.