If only if it was that simple in todays world. There would only be a chance he was, but its still a chance. On the other hand, having a millionaire fighting (on the back lines) would be good for morale (and publicity). Who would have thought a comedian would have been a great wartime president, or Klitschco will be seen with a machine gun and bombs going off in his town.
I personally dont think either of them will either, but theres a chance and they may actually want to for themselves, or be seen to doing the right thing - like thousands of other Ukranian lads, rich or poor. As Zinchenko says, if he is called to fight - he will. No doubt Myko is just as brave.