As far as “rescue” horses, I follow the rescue groups local and regional to me here in Canada. I would say it’s about impossible to source a rescue horse that is sound sane and broke. The horse will be sweet pretty and trained but you have to “manage navicular.” The horse will be sound and sane but a grade yearling in the fugly stage. Etc.
Things may be different in the US but where I live it’s vanishingly rare to find a rescue horse that I would want to take on as a project. Because if he’s got any cash value or is useful as a care lease, he doesn’t make it into the rescue pipeline.
North America does not have the depth and breadth of WB breeding as Germany and WB in the pedigree is an automatic extra $$$.
On the other hand there are certainly enough mediocre WB horses here, or WB x TB and registered something like Canadian Sport Horse because the OTTB mare isn’t accepted by any WB registry.
When I watch the Pony Club moms (usually horsey themselves) sourcing Trade Up horses for their growing teen daughters, they are coming back with various junior appropriate WBxTB, TB (not fresh OT), QH, QHxTB, etc. Some registered WB in some regustry. These aren’t dressage specific, though, more focused on jumping.
Other mixes I have seen make nice horses are Iberian x WB, Iberian x TB, QH x Friesian, QH x ASB.
My guess from a breeders perspective is that it doesn’t necessarily cost less to breed a meh horse than a s superstar if you are doing it right. But the sales price will be less. That said, most smaller breeders are not going to be creating top prospects and even if they did luck out with the frozen semen on their nice enough mare, they aren’t placed to market and sell the foal into the top tier where it will be recognized.
Dressage is tricky too in that a talented horse that falls into the hands of a crap low end dressage program ends up moving and acting crappy, stilted, getting repetitive strain injuries, etc
most of that
