The "fire" (as you call it) is meant to convey a feeling of power and heart--the sort of emotions that are built up and released in a warrior when charging into battle.
As for CnP, why should I spend hours of my time in an attempt to make a crappy drawing of a grunt when I can get a professional-quality one that fits with every other graphic of the game in only a few minutes?
And finally, as far as "lack[ing] anything beautiful" is concerned--well.. take a look at your avatar, bub.
how is that a warcry? it looks like a friggen grunt on fire, or is that really fire?
try pointing out what you're trying to mean, this icon is hard to catch. a battle cry wouldbe an upclose of a orc's face and him having an angry face screaming for hate towards a minor.
also do not make your icons with the help of wc3viewer, a blatant CnP or anything including a CnP definitivly lacks of anything beautiful