Commissar Draco
Codexia Comrade Colonel Commissar
One thing about Gavelkind is that it doesn't split up counties, so if you own every single holding in your capital country then your primary heir will inherit them all, even if it means some of his brothers end up landless.
This gives you a strong and compact power base, but of course less taxes than spreading your demesne across many counties, since you wont have many mayor vassals. As a bonus each holding in the county can benefit from the marshal's levy buffing mission, giving a significant boost to your personal army size.
With the Old Gods coming up it seems like it's time to get used to gavelkind
-Spectacle
I am well aware of that, but I've held 8 core counties in the Latin Empire and I loathe to split them up between my future sons.
I can no longer remove a heir from succession by gifting him a church
Perhaps if I captured Rome or other Church based counties I would be able to do so...
Gavelkind is useless if you're into Kingdom building... but this is optimal system if You have single big Duchy like Tulouse or Provence... BTW new 2.11 tPatT crashes a lot.