The usage of the plural guys in the phrase “some guys chased them away” would generally be assumed to mean men rather than women. When used of animals, guy usually refers to either a male or one whose gender is not known; it is rarely if ever used of an animal that is known to be female.
The guys were busy trying to outdo each other. It is challenging to work with men who are trying to outdo you. Verb be more successful than. "the men tried to outdo each other in their generosity" synonyms: surpass, outshine, overshadow, eclipse, outclass, outmaneuver, get the better of, put in the shade, upstage; More