I think we can all concur on Bird's passing and playmaking ability. On the other shoe, I think really Bird's the team's best rebounder, given that he wasn't assigned the paint patrol role like Parish. Remember Riley's adage... he who controls the boards, wins the rings. In this case, Parish/Bird = Cowens/Silas.
However, I'm a bit confused here about the nature of some of the arguments posed. Was McHale mainly an effective scorer because Bird was feeding him the ball or was it that McHale was a prolific scorer, because the typical low post defenders couldn't keep him in check, with his non-stop varying post moves?
The reason why I pose this is that in effect, a team can usually put their best defender plus best co-help defender, on one person. Thus, Bird always had the attention of any opposing teams defenders and hence, he was all over the place.
For McHale's case, the situation would be more like this ... defenders will look to keep him out of his scoring perimeter and thus, have a bit of a problem since the person they really need to focus on is Bird. In this case, McHale would be less of a 'black hole' because in effect, his offense is what's trying to be limited by setting up a wall in his scoring zone, and then, he'll be a passer out of the post, perhaps first finding DJ, and then DJ out to Bird, if Johnson doesn't have a clear look at the basket.
All and all, making McHale's offense option number one, makes the 80s Cs more formidable because as you know, it's easier for Bird to go lights out, from time to time, if others aren't all over him from the get-go.