Hi I've been playing Rome for awhile but never used any of the recruitable siege weapons, probably because I find siege battles boring and often autocalc them. I've been considering siege weapons lately because due to the incredible number of full stack armies the enemy fields I am attacked from behind nearly every time I lay siege.
My question is regarding their effectiveness. I love ranged units, usually including five to six archers in my legions to conserve my units. How effective are the onagers for anti infantry work relative to archers? Are ballistas any good?