The question and your problem is based on a lack of logic and understanding. The gender of a noun in Latin is imminent for that noun. For sure, on a verb/predicate in a sentence can be applied several genders: Servus clamat - the slave cries. AND: Servus et serva clamant. The slave and female slave cry. If you have more, then you use the plural of the nouns: Servi et servae clamant. I do not really see where your problem is. However, I hope it is clearer now.