No he is not crazy, survival is broken. There is no ''boost'' but for your team the gear works like this, it takes total and gives 1/4 to each ninja, just like secondary and third ranked teams, so it evens it out, makes your tanks less tanky and makes your fastest guy slower by giving some stats to other characters. For your enemy gear works normal, that's why they are faster even with worse refines, because your fastest guy is sharing his speed with others.