To be perfectly honest, torque is probably one of the more better engines to do this on.
It's not. Unity is probably not a good engine for it, I agree on that point, but only because it's a well known fact that they don't handle lots of dynamic shapes well. Unreal engine on the other hand is a completely different story. Just the fact that it's eons ahead of T3D and TGE makes it a ton better. Yeah, it's more advanced, but that's the price you pay for a better all-around game.
Unless you're saying that you can't make it in any other engine because of lack of experience. In that case, there's really no point in doing this because you won't make any significant improvements. As Badspot and Rotondo said, T3D is just not a good engine to use with for a blockland-style game. They're experts on the engine, and this is not an insult, but none of your dev team is. None of us have the experience that they do.