Support, financial or otherwise, to participating foreign (usually US) troops varies. They have a completely different political and military structure and their budgets for such things are subject to a bunch of factors. Their system, especially the National Guard, still confuses me thoroughly and seems to confuse many of them.
We want them to come and play, so some enticements are necessary. Quality of training is one. Guard units have one weekend per month and two weeks of summer training and that's it, aside from pre-deployment work-ups and taskings. That's very little for an aviation unit, in particular, to maintain currency and competency. They therefore have to squeeze every drop of value that they can from every opportunity. Variety is another - they haven't even seen Pet let alone memorized it like the training area that they go to year after year ("the same old Camp Swampy" as one put it). They get to work and socialize with new people with different backgrounds and that always adds interest. We also have geography on our side: US military helicopters can only fly tactically within the boundaries of military training areas, whereas we have authorized Tactical Low Fly Areas that extend well beyond. The North Tac Low Fly at Pet is all across the Ottawa River, about 5500 sq km of nothing but hills, trees, streams, swamps, and the odd logging trail. No inhabitants to scare or annoy, and excellent contours for nav training. They have nothing like that. The intent is to make it mutually beneficial, however other arrangements may be negotiable.
And the only people who have to apologize to Griffon crews are the ones that bought it.