5 and 6 seem normal depending upon the amount of time one spends on IQ, the potential of the player, and the WE of the player.
D3, Muskingum, in Dobie has a Jr. DL with a 98 WE. He has gone up 19 points after three exhibition games but no category went up more then two points. He is an outlier on his team and some players haven't gained anything. With that WE, and if he is a STL player, it seems reasonable, especially if the coach isn't spending much time on IQ. Also, the categories themselves could have been right on the verge of changing. I assume the numbers are to the hundredths place but we only see the whole numbers. So, they each may only be 1.1 units of growth but appear to be 2.
I'm probably wrong, but this is the best I have for an explanation.