My Hawk Saw pulse rifle has 244 attack and i got it from a primary legendary engram, whereas the one from the vendor has 280 atk. The same for my other legendary weapons and armour, which I've received from rank up packages and engrams, some of which have as low as 221 def. They all required level 40 to equip. Does this mean i have to buy the vendor loot to infuse my existing loot? And if so, what's the point? Why not keep the new vendor stuff and dismantle the old one? Can someone answer?