I can only compare what was going on with JP when he was about to take over the starting role and what's going on with Greg.
Brodie was constantly working with JP to be able to understand what defensive schemes/sets he would see when both were working out at the QB position.
If there was one concern I had it was that - JP would struggle in that regard.
Now, this is a supposition, but a logical one, that one of the reasons JP focused on a single receiver was his pre-snap read. If he was still struggling in his Jr. year there's a chance that struggle was magnified with his post-snap reads.
I've often referred to Greg as a "real heady player." He's got football smarts, much more so than JP did when he was at the same stage of his career.
For that reason, I think any characterization of Greg being a JP part duex is far, far too premature.
I've seen the mention here a few times of "game manager." Yet, while we heard Saban say that last spring I've yet to hear him mention that phrase once this spring. (haven't watch his last presser if it's there)