[X] [War] Focus on Warlord Levina and her horde.
[X] [Haven] Welcome both the refugees and the former slaves. (???)
Our allies can handle the southerners on their own. They've got more troops, better troops, a Martial hero, and other heroes besides that to help too. Meanwhile, we have to fight 10k cavalry, when we have, in total, about 25k infantry with 3k cavalry. That is sufficient. What's insufficient is fighting them with only 12.5k infantry and 1.5k cavalry. We're going to need the entirety of our army in order to stop the nomads from hitting our allies or our heartlands.
We should definitely welcome in everyone. We have enough Temp Econ to feed all the refugees as they find work and we have enough Temp Mystic to effectively integrate all of them. Additionally, the update said "Many of the former Forluc slaves would find themselves without jobs, livelihoods and lives in general", so if we refuse them, they will burden the Forluc, as the Kingdom would have to feed and house them even as they don't contribute to society. From both a practical and moral perspective, accepting both the refugees and the former slaves is easily the best thing to do.