If there's shielders, with 6-7 shield skill, they already have the 18-21 agility.
Making it "only" 5, just for the others is... a shame, since shielders will walk with their shield up, so slower, whereas pikeman and 2hander can walk at their fastest speed, so they need less.
Pikeman and 2h with 4-5 athletics is fine.
Shielders should definitely have at least 6 athletics, 7 better imo.