Cannot see how there Americans *wouldn’t* be there - at least contractors.
You can’t just hand over the keys to these systems... especially to a bunch of shitholians who’ve never touched them.
Officially, other than mercs/volunteers serving in the Ukie Army, there are no Americans there.
Unofficially... well, we all know what the CIA and such do.
Now, that said, ostensibly this equipment came with crew training in the US after the Russians blew the crap out of several training areas that had been set up in Ukraine and there were no advisors or contractors in the combat area. The vehicles aren’t even being repaired over there, but they’re being shipped back to the US - and the damaged vehicles have been seen and photographed here.
Exactly, anyone who believes there haven’t been Americans with boots on the ground since day one is incredibly naive about how modern armies fight, and not just contractors. Supporting the fires chain starts at the sensor; could be space or could be deep HUMINT which one way or another will be mediated by some kind of special operations force likely with spooks, and doing this, as well as developing targets and clearing fires is not something shitholians can do without a lot of help.