I have fought over my husband more times than I can count. Most have been due to jealousy and many I actually instigated myself because I know just how much he's aroused by my catfighting. I will continue to do so for as long as I can. But simply put, a fight for cock , is basically a catfight for a man, the dick just happens to come with him.
The only time I might actually "fight for cock" is if I'm sharing a blowjob and the other female refuses to let me have my fair share. Then it will certainly turn into a fight over a cock.