Probably, lately in my Romans campaign in RTR I have been using an odd heavy infantry as my mobile force. They have been a bit slow at times and end up spread out and vulnerable, but the enemy is scattered when they scatter so it doesn't do much harm. Mostly I have had trouble getting enough cavalry and skirmishers so my Triarii and Principes would end up chasing skirmishers and routers across the battlefield. An odd highly aggressive heavy infantry tactic that I developed by accident, only problem is when I fought the SPQR army I lost EVERYTHING. My best general barely escaped alive. Besides that though I have only lost a couple of battles against Carthage and one siege where I was totally overwhelmed by a much larger force.