Avoca male lions

[Duco Ndona]

I dont think they have lack of confidence. They just didnt want to get into needless fights. 

The Avocas largely snipped off small parts of their territory. Which may be insulting, but it sofar doesn't endanger the Birmingham Males position. 
They can just retreat a little bit further south. They still have just as much control over the pride as they did before and if needed, they can just go back and reclaim the land once the Avocas went home.
So it may not be worth getting wounded over. 

Othawa male just barged in, went straight for the heart of the territory, likely ran into a part of the pride with cubs and by doing so tossed in a open challenge to the Birminghams. 
Thats something you just cant ignore. If a rival lion does that, you either flee or attack. Reply