Considering current stage of pvp (tombs/gvg) melee assasins wont exist. Why ? Because every serious team is using some kind of prot against warriors/rangers (i.e. melee ward, aegis, guardian). Because assasin is based on combos he wont be able to execute combo with more than 3 attack skils (3 when really lucky or with full team of assasins). When warrior misses with an attack he doesnt lose all adrenaline but assasin have to wait till his lead attack recharge to do anything more than bashing. It would be much better if assasin would have to execute prerequisites attacks but they wouldnt have to land on target to execute another attack. Simple example: I start with lead attack - it misses, but then i can execute offhand attack - it hits.