Most QH's have TB in them as the AQHA accepts (or did accept) Jocky Club Registered TB to be one parent to an AQHA registered horse. All Paints registered with APHA are QH or TB based as the parentage for APHA horses must be either both registered APHA or one reg APHA and the other parent must be AQHA or Jocky club registered. APHA is not just a "color registry" only certain breeding is allowed.
So, there can be a LOT of TB in some Paints. Cinny is APHA but if you look at his bloodlines he is more like half QH half TB. This would give a better conformation for Dressage and makes for differences in individuals just like it does QH's.