have never really been in a situation to make rams, but am now but of course know nothing about them. Are they good against AT's? Archers? Cav?

Should I use them in a wave on an attack and should they be the bulk of my attack, equal to arch, or less?

I mean, I don't want to make 1k of them if that is worthless. At the same time, I don't want to make 100k of them just to do something stupid with them and have them mowed down.

Just curious as I go forward.