So I want to make an AOE farming Group of 5 (4 being controlled by me 1 being controlled by my g/f)

My only question is, are mages able to cast Blizzard Via Macro? I don't think they would be, but it is possible to do a /cast blizzard party1? That way my Paladin goes in and aggroes, then my mages all cast Blizzard. Any suggestions about AOE farming would be great. Thank's in advance.