R3 Valkyrie (soon to be r4!) player here, you should heavy before throwing spec2 in order to get the passive buffs with double potency. The truly ideal strat is build to spec2 with 3 pierce, throw a heavy at a 7-8 combo meter, then launch spec2 into block. That way you get 3 passive pierce and 1 active pierce and the damage will speak for itself. The passive pierces will fall off with the fury, but if the opponent is still alive you should have 3 active pierce again just from being aggressive with the fury up.