Hopefully this does not come off as rude but the facilities really should not stop international teams.
Think about it, a lot of the best gyms in the US started without a practice space at all. I've seen videos of WC Shooting Stars practicing on wrestling mats in the late 90's I believe? These facilities don't just appear out of no where. A lot of coaches spend years working towards owning a gym and often times put their entire life savings into it. If owners, coaches, and athletes push themselves to become a force to be reckoned with on the international level, they can do it. Honestly, the level of dedication, heart, and passion for the sport is really one of the biggest reasons allstar cheer has evolved so much.
Plus, the US isn't necessarily the only top team in Olympic gymnastics. So there is obviously some sort of basis for tumbling there. It's not like we are the only country who knows what tumbling is.
If you'd like some insight to US cheer and how it really works on the inside (at the gym and all) to help out your program I'd be happy to talk :)