Welcome! You may want to check out the Crossbreed campaigns and see what sort of Warmblood you might want to try that already has a campaign going. You may be able to find horses for sale (from president or members with stock in that club) or up for stud/brood from the club. Also if you Halter show your horses, if they qualify for the campaigns you can enter your crossbreeds in halter shows; otherwise, you can only do discipline or career if they are a generic crossbreed.  You can also see if any of the ones that include the Welsh ponies are of interest - just watch out as it matters if it's A, B, C or D in the campaigns. :) 

https://horsefable.com/crossbreed-campaigns

Hope you are enjoying the game! Have fun with your projects. ^_^ 

There's definitely some interesting mixes out there ! I'd like to create my own campaign actually to make Anglo-Euro Sport Horses. I'm working on my pre-F1 by making different crossbreeds of Hanoverian, Dutch Warmblood, Thoroughbred and Andalusian. Where could I post a topic to see if this campaign would interest them ?

Crossbreed campaigns are a ton of work and cost a lot of money to make happen and you will need a lot of people. Plus, that is a lot of mixes to put accurately into a breed

I am very aware of what crossbreed campaigns entail. This is one of the main reasons I joined this game as it is a feature I appreciate.