if I simplify a little, Umathela is Malkion/Orlanth (Orlanth mainly on the battle field) and Fonrit is Chaos (or Chaos friendly).
The conflict is territorial (as in the Season wars), but also religious? Is Fonrit seen as 'Chaos' for the Orlanthists? (a little bit like the Lunar were invaders but also 'Chaos related'). the Slave (Fonrit) vs Freedom (Umathela orlanthists) is obvious.
Is there Uroxi in Umathela? Because there is not big Chaos nest close by (except maybe Fonrit)?