Roberson gets a lot of credit for being a great rebounder and that's just not true. The box scores speak for themselves. He has 45 more rebounds than Taurean playing 99 more minutes. That's an hour and a half more playing time. TT rebounds as well if not better than Roberson.
In that huge minute differential, Taurean has 45 turnovers (not good) to Roberson 35. Thompson has more steals and more blocks. He's scored 294 points to 177.
I mean pick your poison. Roberson is a senior. Tauren a freshmen, who does as many things just as well and he scores points.
As far as defense, yeah it doesn't take a rocket scientist to see that Taurean doesn't move his feet very well but it's also hard to measure personal responsibility playing in the zone. I'm not enamored with Roberson's or Lydon's defense either.