You are imagining it wrong. The movement will never match a warframe. If you really have to think about it, imagine a necramech fighting a Profit taker with head tracking. Make the side step inclined with the head tracking and not loose any speed ( I believe the mech sidestep still need to be fixed) , thats the movement part done. Lastly , snap an archwing on the mech with head tracking active. Archwing already have movement similar to that we see in AC and just missing the head tracking part. Add some big guns/ ability that is actually useful (i mean rocket launcher, could be similar to seeker volly). I don't see why you think it will turn into a bigger warframe.