I used "landowning vassal" to more easily allow for the creation of any new ranks between Count and Baron without having to both make a rule change adding the new one and changing language in the old one. There is also the issue of counts swearing to eachother, likely to happen with larger Houses (at least if their dukes try to keep them very hierarchical, you could also just have multiple branches down from the Duke).

With prioritized units the Chancellor loses some of his power. I'm not sure we should take away his power to control what exact units are recruited. If the position gets too weak people might be less inclined to run for it. It's a lot of work as is...