For ram attacking infantry, how about we give it a slight damaging aura instead (unlockable tech?), this simulates the soldiers inside the ram retaliate against attackers, also with this aura the ram doesn't have to stop to attack enemy units and can still sort of push forward given enough time. This way we can silmulate the fact that ram can still be blocked by enemy but it can slowly bowl over opposition, but clearing the blocking enemy with your own units will be more effective though.