@BOTMAN
Well, I'm sure he must be getting used to this world which is considerably more primitive. He has been involved in war and has hunted to bring food.
I really don't think there's anything wrong with eating the horse.
However, I do wonder if it isn't a mistake to allow pillaging. It's one thing if the pillaging concerns the ruling class which has amassed wealth and you're just taking wealth back home while replacing the ruling nobility with your own, but if you're looting from the common people they will not simply remember the war as being a problem of the nobility; they will hold grudges against the enemy country, they will be poorer from having lost their belongings and so they will join the army, get paid as soldiers and have the possibility of retaliating in the same manner. Then there's the fact that he will be completely unable to use the Exus tribe in a civil war because pillaging from his own countrymen in order to establish himself as the king is not a great idea.
With that said, I was under the impression that Dormorgar was going to be on the offensive while Rosice would be defending itself, so the opportunity to pillage should be scarce, but still it wouldn't be surprising if land was ceded if Dormorgar loses the war. I guess he can always pass off the pillaging as acts from the exus tribe and establish policies to provide help to the newly conquered people to lessen their grudge. As long as they don't kill while pillaging civilians it should be ok. The belongings of civilians probably aren't worth all that much so allowing pillaging in their alliance but then proposing to give bonuses if they don't pillage is a possibility. He could also just have them pillage, then pay the civilians to rebuild and make his money back in the long term through taxes since he'll have the land.
Well, we'll just have to see how that is handled. Right now, this is just an oral agreement between them too. They don't have anyone recording this nor witnessing this. The exus can't even be sure the alliance will hold since King of Rosice is sickly and all they have is the assurance from our MC that the next king will be favourable to the deal he strikes (of course, we know that the next intended king is going to be the mc).