Ganimal
Recruit
At first i only have one City, "Myzea" looked for Mesui cause i know she's free and doesnt have to pay, I got her and when i'm just about the siege a castle (Northern Empire Castle) with her to give it to her then she left. after a long battle i manage to weaken the northern empire with the help of Khuzaits (not allies just same enemy) recruit Mesui, and got a castle for her. then a few hours or game days she left again "WITH THAT CASTLE". right now i got 3 Cities and 2 Castles, and all of my Lords Mesui (free), Pharon (free), One Lord from Aserai (paid) left. im so done bro specially i paid almost 3M for that aserai lord and got my money back to thousands. its like Mercenaries are better which i have three Mercenaries clan
and also this is a fresh save from e1.4
IIRC, Mesui is has devious trait? Perhaps they defect / leave easier than honorable ones? Also, I have had lords leave very soon after convincing them to join with out quickly giving them feifs. In my previous save (beta 1.3), I was able to retain lords i convinced between wars by proposing to give another lord's fief away to them, or strategically timed a lord convince right before I besieged and taken a fief. Hope that helps!