If you make something like this:
9 8
15 11
14 12
9 7
7 3
You could either add 2 PA to get to 99% cap, or 3 JS and 2 JR. I'd take the 5 pops JS/JR at that point. With low potential I'd always look for a more balanced player because you can get more SP stuffed in that way. Maybe even go for
12 11
15 11
15 11
9 7
7 3
Both builds could be trained more IS/ID/SB of course, don't know how far you want to go there.