As I've mentioned before with Thomas Robinson he could be 6'7", 6'8" or 10'6" and the problem would remain that he is just not what you need to put next to Cousins. If he can carry the rebounding over and defend his position at the next level he's not the worst guy you could select, but he'll never be that help defender we need, he doesn't have that faceup jumper that even a guy like Jason has to keep the middle open, and he's another one of those older rookies who may not have the upside to change the script.
Now assuming, and I think its a safe assumption, that if you draft Robinson, who was not even a shotblocker in college (less than 1 a game) you still need to get that interior clogger to go along with he and Cousins, and thus you would have to let JT go and basically replace Jason with Robinson, the question you have to ask is this:
Jason Thompson, as a starting rebounding but non-shotblocking PF for us this year averaged 28.8min 10.0pts (.535FG%) 8.0reb 1.3ast 0.8stl 0.8blk on 7.5FGA a game in 47 starts. How much better a statline in Thomas Robinson going to give you on 7.5 shots a game while having to share minutes with a mysterious shotblocker to be named later? And if you start giving him more shots, who is he taking from? Cousins?
Fact is that the only way a new guy can come in and help us beyond what Jason was helping us without magically stealing even more shots on a team that has absolutely none to go around, is for the new guy to be a major defensive force that can elevate the team while playing without the ball.