To thin to play center?

I was wondering what people thought about the validity of the following very rough calculation in evaluating centers for bulk: a simple weight/height ratio. Obviously, it is inadequate on its own and can only be understood along with height and body fat, etc. But, as a quick indicator and with a general understanding of the players' build otherwise, would it be misleading to look at this ratio to measure a player's bulk inside?

Using ESPN height and weight figures, a couple of centers look like this:

Name..............Height..........Weight..........Ratio
K. Clark.............83.................220.............2.65
K. Willis.............84.................245.............2.92
B. Wallace.........81.................240.............2.96
S. Bradley..........90.................275.............3.06
K. Cato..............83.................255............3.07
Mutombo...........86.................265.............3.08
T. Duncan..........84.................260.............3.10
K. Malone...........81.................256............3.16
Yao Ming............90.................296............3.29
E. Campbell.......84..................279............3.32
S. O'Neal............85.................335............3.94

I was surprised to see Kevin Willis so low on the mass scale, given his strength. I was also suprised to see Yao Ming soundly beat guys who are never criticized for being too thin or weak, like Tim Duncan, Karl Malone, Mutombo, and Ben Wallace. And finally, I was surprised by just how much Shaquille O'Neal beats everyone in a height/weight ratio. He is a big, big boy.

 

Some early reports had him listed at 240, but I thought it was pretty commonly accepted at this point that the legit measurement was near the 300 pound mark. Besides that, given that he and Bradley are the same height but Yao's legs are 3 times the size of Bradley's, I just can't believe that Yao is actually lighter.