I agree with the others. Why not split the commercial practical? Takeoffs and landings in the 210, everything else in the 172. A 210 is a heck of a lot of airplane for training in anything other than how to fly a 210.
OTOH, if you want to learn the maneuvers in the 210, 2 questions:
1. have you been flying the other aircraft "by the numbers?" Are you doing so in the 210? IOW, do you know what power/configuration settings will get you the performance you need? I'm asking because a lot of pilots are not introduced to the concept until either instrument training or complex/HP transitions. Knowing the numbers helps with...
2. Are you setting up for the maneuvers well in advance? Even for a student pilot doing basic ground reference maneuvers in a 172, it helps a lot to be stable on airspeed and on altitude =before= starting the maneuver (with, IMO, not being set up the #1 reason for screwing up the maneuver). That is going to be far more of a problem with a much more powerful and faster airplane. If you're still trying to configure the airplane for the entry speed on a lazy 8, you'll still be fighting with it when you (unsuccessfully) complete the maneuver.