Think of Potential as How many ounces the glass can be filled. The bigger the glass(higher potential) the better the player can become.
WE can be thought of as How Fast it can be filled.
As far as potential , you find that when you send assistant coach scout trip to player. The message will tell you the potential. You have to be able to interpret the messages though.
Can someone put a link here to the post with the assistant coach scout trip Messages ?