Even then, I think ladders would be better since a siege ladder can have 20+ infantry behind it. I imagine if they ever implemented stakes you would only be able to get 2 or 3 infantry behind it. But then again, stakes would stop a horse completely, the ladders only bring them to a crawl for a moment, and then they can accelerate again.
I think it's a pretty shitty tactic (although very smart, and you're pretty dumb not to use it against cavalry) to throw ladders all over the ground.
Maybe a ladder that's deployed on the ground would disappear after a few seconds? I don't know how that would be easily implemented though.
