Your reasoning is very very flawed.
When you buy a weanling/young horse, it is very hard to look at that baby and determine what it will look like exactly. However. Looking at both parents gives you an excellent idea on what the baby will look like. You are wrong in thinking that a baby will grow up 'nothing like it's parents'. Perhaps in color, but not in conformation.
Why?
Because conformation is genetics. The stallion Mosaic has one of the WORST hind end conformations I've ever seen. His croup is terrible. The other stallions have other faults--most of the mares are pretty terrible conformation wise. None of them are APPROVED (I'm not talking about registered) with a warmblood registry. And NONE of them would pass. They breed stock horses (APHA Paint horse) to a draft--and these horses make TERRIBLE sporthorses. Not to say they're not good at other things, but if you want a sporthorse, those are not what you want.
Conformation--GENETICS--are VITAL to a foals chances of becoming an amazing horse. If he is built correctly, he will not break down due to crappy conformation, he will have an easy time transferring the energy created from the hind to lift the forehand, he will jump better, he will have talent (movement and jumping come from the parents--you can't train movement and you can only minimally train a jump), and he will even sell for much, much more if you end up wanting to sell him. Weanlings bred from parents with odd breeding (Paint/Draft) and BAD conformation ONLY produce more of the same. Why would you think otherwise? This is simple biology--not an opinion.
When you pay more for a weanling, typically you pay for 1.) Bloodlines. Bloodlines usually equate to natural talent and athleticism. These horses can also be REGISTERED and APPROVED in warmblood registrys--MOST warmblood registrys will NOT accept Stock horse blood (APHA paint or AQHA blood). 2.) CONFORMATION. When you buy a baby from good parents with good basic movement and GOOD conformation, you will not get burned (provided of course he doesn't get hurt).
You are attempting to make something out of nothing. These are the horses that get frustrated with their jobs, get injuries frequently, have ulcers, and hate work--because it is very hard for them--if not downright painful or impossible--for them to do what you want.
