Well, we've already been without van Persie for most of the season, and he's had an awesome strike rate when he has played the last couple of seasons, so that's like saying it'd be interesting to see how Man U would do without Ronaldo, or Tevez.
We've coped without van Persie and he'd quite possibly be our top scorer if he'd been fit. Plus Eduardo and Fabregas have both scored more than all, but 2 United players, van Persie, Rosicky and Bendtner have all scored more than all, but 3 United players and Hleb's scored more than all, but 4 United players, so we're not too bad for goals!