Yah, my males fight once in a while, but there's just 2 pairs in a 50 gallon, so they keep it to a minimum... Mine had a wound on his head for a few days from fighting, but it cleared up really quick. I'm betting your male will pull through just fine, must have just gotten too close to one of the females during feeding time (never get between a woman and her blood worm).
I wanted to do macs for a while, but could never bring myself to plop down 80 bucks for a male. My channoides are breeding regularly, but the males are swallowing eggs after a few days (probably because I keep tossing food in there). I'm hoping to get them synced up next week so that both males are carrying eggs and I'll put the females into breeder boxes so I can feed just them. If that doesn't work, I'll just stop feeding when I see males carrying eggs.
You'll have to let us know how this turns out though, macs are just freakin awesome.