Tribal alliance unintentional impact

[Stringer1313]

When I declare a tribal alliance, sometimes several of the tribal units will become red (I think maybe because they are raiding another Civ?), but then those red units will turn on the tribe's units. That's b/c now the tribe's units are on your side, and red units are against you, so they must attack them. The tribe starts consuming itself -- I saw one tribal site become a barbarian site after allying with me!

Just wanted to point it out -i assume it's unintentional.