The most UNPOPULAR faction in Heroes 5.

imagine what would happen if a hero has no magic; the gargoyles would still lose. You can't keep flying away forever.

You absolutely can. The hero eliminates these stinking chunks of decay with a regular attack, and the gargoyles simply run away from them. It takes a while, but it works.
Seriously, it's great to see you writing the same thing over and over again. Are you waiting for a comment? Well, here you go; you've got one.