I always ran things like that as the weaker races being enslaved or otherwise convinced to do the bidding of the stronger ones, made sense to me and the players never questioned it

That reminds me of one adventure I ran, the players walked right into the middle of a battle between a group of goblin tribes and an orc army Total chaos! Half the time they would come upon groups that were taking potshots at each other and ignore the party entirely, other times 2 groups in the middle of a pitched battle would drop everything and band together against the players

Great fun!