You have 10 ap. Ap stands for ability points. I have acrobat on my 4 defensive backs. Acrobat only coast 1 AP. So that leaves me with 6 more AP o can spread out in my defense. There are some abilities that take up 3 AP. Like enforcer and One step ahead. The 10 AP is the cap for abilities
You could literally have all 11 if you wanted. 3 X factors and 10 Ability points.
You can put 3 xfactors on with 0 ap. Then abilitirs on 4 others. Not hard to do
Dude has 3 LBs active, 2 DL and 2 CBs.