So essentially it would be calculated like this:
Grade 5 character.
Attribute:Agility(3d6)+Skill:Shield(1d6)+2(medium Shied)+1d6(High Quality Shield)+2(Size: Small)-(medium Armor -2, reduced to 0 from 3 ranks in Armor: Medium)+2(Exploit Shield bearer)
Capped: Attribute:Agility(3d6)+Skill:Shield(1d6)+1d6(High Quality Shield)
Uncapped:+2(medium Shield)+2(Size: Small)-0(medium Armor -2, reduced to 0 from 3 ranks in Armor: Medium)+2(Exploit Shield bearer)
If I have understood your post correctly here and in
WOIN - Capping Your Dice Pool correctly?