Nah, that's nonsense. :)
“Strength” stats for the hero and units are just as important as magical stats. You just need to combine everything. Focusing solely on strength or solely on magic puts you at a disadvantage compared to someone who can manage both equally well.
Personally, I try to take magic in combinations – for example, WATER with a prayer spell :cool:, and AIR with lightning to deal damage :smile14:!!
