Because, a warrior CAN always permalag you, unless you have bash protection. Sure, you can change your size, but they can change theirs. Sure, you might be a giant (but not many magi are), and this bit of the thread started talking about magi fighting warriors.

I don't want to explain why dying to a lowbie necro requires a cock-up or people won't die to them any more. Safe to say that everything you need to survive them is either on sale to even lowbies or can be picked up off the ground, unless you allow them to summon you to a place you cannot flee from, or chase them until you are so low on moves that they can ensure you can't flee when you wake up after a few hours of scourge (or if you don't realise the danger of energy drain early on in the fight).