High block is utilized by the 5 in a 2-3 better than anywhere else. That doesn’t make it the highest priority for the position. Even if it was, B’s 25 point advantage in block has to be considered alongside the 35 point deficit in defense, and the 10 point athleticism deficit, and the IQ. So before you even get to rebounding (which is another big deficit), you’d have to believe that block is *far and away* the most important defensive attribute for a Center in a 2-3 zone to consider this change. Easy answer, I think.
Now if they are your best 2 bigs, and the question is just a matter of positioning, then yeah. Player B at Center, player A at PF.