As mentioned, Jordan Bell is taller/longer than Ben Wallace and Draymond Green. The player he most closely resembles in terms of measurements and athleticism is Josh Smith and Smith was top 3 in the league in BLKs four times back in his ATL days, is 27th on the career BLKs list and 3rd among active players (he has more career BLKs than Serge Ibaka, Tyson Chandler and DeAndre Jordan) . Smith has a slight edge in standing reach and leaping ability, but Bell has a much higher motor amd has not yet displayed a tendency to jack up a tn of ill advised 3-pointers for no apparent reason.
Bell is also taller, longer and much more athletic than Paul Millsap, who was 5th in the league in BLKs in 2015-16.
I am not at all worried about Bell's shot blocking translating to the NBA level. It will be his biggest strength.
BNM