What Lee is saying is that you may add warren's 16 or 18 or 22 points a game, maybe 5 boards, 1.5 steals, 3 assists (just guessing at #s here). But you have to subtract the contributions of whoever's minutes he took. the net gain would not be that simple. (keep in mind also, that he would have been the focal point of defenses, so simply pointing to last year's #s and saying they would have improved is dubious logic)
He also raises a good point, in that it changes other facets of the game for BU and for Bu's opponents.
I am not going to say we would have won X number of games if we had AW, although i think most would agree that we would have won some games we lost.
What I will argue is that if we had AW, we would have seen SM's #s improve, as he would not have been who defenses key'd on. SM gets more open looks, defenses are spread out more. TW gets more lanes. Even DC might have had less turnovers, as that's one less defender to step in and swat at the ball.
As for WE, i think he would have helped, and probably more so as the year went on. We can speculate, but we don't know for a fact what could have been. Next year we will find out more.