On long haul international flights while United might not have the minimum number of FA, they seem to have minimal. We already know at least one was cut since meal service was streamlined. And generally speaking it seems like crews for European or Asian airlines for a widebody are much bigger than when I see United crew waiting to board.
Also I’d be surprised if a crew member would be rushing to work another flight after a long haul flight. Not only would they be over their hours, but you also have potentially customs and passport control to get through.