There was no clan wars in pre-colonial times, there was competition for access and control but people allied with eachother across seperate clan lines. For example Majerteen supported 1 faction of Isaaqs with another faction of Isaaq connected to Zayla fighting over control of Berbera and it ultimately ended up with the creation of the sister port Bullaxaar.
But overall most of the major conflicts were around separate governing philosophies and expansion of trade. Hobyo vs Majerteen , Bardheree vs Geledi for example.