@TrillovinumHopefully the war isn't a complete cop out before it has the chance to start. After all if you look at some of earths actual, modern day civil wars and keep in mind that this war is a three way civil war with alien powers playing puppetmaster by supplying weapons, training and possibly troops and at least one foreign power actively pushing to take a foothold, this is not a war that is going to be over anytime soon.
Even if it was just between the Elder and Middle brothers, what springs to mind is the Nazi Germany and Soviet Union battles of World War 2; One side (Starting off at least) with highly trained, professional soldiers who are equally highly equipped while the other has much less training and equipment (And what they do get is questionable) but a crap ton of man power and a command that doesn't care if people die but will throw a fit if any of the guns get damaged. Still took ages to end and it only ended that quickly because Germany was fighting on many different fronts at the time.