Interesting Move by Ba al, I must say. To go into another war when already fighting one is an interesting move for any tribe, and there are usually only two reasons:
1) the first war is an exercise in steamrolling, and the tribe want more targets/ a challenge: this doesn't seem to be the case, as if it was then the stats would be a lot more one-sided...
2) External pressure. Now, I know that O F A are saying that they had nothing to do with the declaration, but one has to ask, who benefits from this?
With Ba al now attacking CB, they are under pressure from two sides, and the nobling stats don't seem to be going their way. This could be a preliminary shift that will change, but it certainly seems that they aren't coping particularly well with this. Not well enough to justify entering into a second war at any rate.
Now look at O F A's position: They are fighting pretty much all the tribes up there right now, and seem to be rolling over pretty much all of them... except CB, who from what I can see are still nobling strong in the area of the front lines. Then, for some reason that I can't really fathom (under the circumstances) Ba al jump into a war with them. This gives O F A a little breathing space, if they needed it, and puts the one tribe that was properly fighting back against them under more pressure.
So really, who gains the most from this war?
If Ba al lose, then they've been wiped off the world, doesn't sound like a winner to me. If they win, they are backed up in the corner, just out of a war and probably not in the best of shape, with a huuuuge family tribe right up against them, and seeing as they just knocked out the only tribe who was putting up a fight against them... not a particularly hopeful future.