The Hapsburg empire, in its various incarnations, existed for almost four hundred years (1526-1918), and most of the time, their troops were loyal, so the answer is yes?

But one has to be careful: while their military was diverse, it wasn't really made of immigrants. It was simply built out of very diverse local ethnicities that were settled in the same place for centuries. Which means, for example, that when the Kaiser fought against the Turks, everyone involved regardless of language had an incentive to fight, because their own homes and freedom were at stake.