I ride with a group of TWH on my little TB cross and on my arabian...im the only non-gaited person in my personal group lol
My arabian has picked up some sort of odd prance which keeps up with the walkers fast walk and her trot is lovely and keeps up with the running walk so no issues there.
My TB cross (we believe with QH but not sure) Can do a slow jog that is equivalent to the fast walk and his normal trot is even with the running walk if not better...half the time he out paces the walkers and makes them have to work lol
If a horse is ridden with gaited horses enough they will learn how to keep pace in their own way just like mine learned a prance of sorts and the jog.
My opinion is that any horse who is in shape can keep up with if not out pace a gaited horse...the key is that your non gaited baby be in good condition!