What really needs to happen, is both states need their hands out of that cookie jar, and an academic consortium with international members needs to define what's in the books- Say, you need to have a good impact score and have contributed to human knowledge in a meaningful capacity to contribute to the curriculum. People that are going to be harder to buy off for "Jesus want this!!!" reasons.
Leaving aside the problems already mentioned, and the serious obstacles to actually getting a consensus definition of "good" and "meaningful", there's one fatal obstacle to this plan: the spam folders of the academics you want are already inundated with requests of this type, because the people who want better textbooks can't offer anything more valuable to us than the time we'd waste on something like this. Grants are an intrinsically better source of funding, salary's what patents and industrial collaborations are for, and all the people whose opinions we actually care about already read our actual work because they have journal access. If it were some sort of legal requirement, we'd just leave while everyone was working out the problems with preventing us filling the books with amusing nonsense out of spite; we've certainly no shortage of places to go, and while America is a beautifully over-funded and under-regulated playground, it is not unique in either respect. In any event, the education system is working well enough for our purposes. We're oversupplied with brilliant obsessives and will be for the foreseeable future.
See, we're very hard to buy off for "Jesus want this" reasons, and by the same token we're very hard to buy off for "I, John Q. Lay-Public, want this" reasons. You're only going to get authors with no future and nothing better to do, and I'm guessing you don't want humanities textbooks exclusively.