I came to leave feedback on this and saw most my feedback already made xD so I agree with the other guy but here's more:

I think the Royal Tree of internal development and reformatting the military should be part of all trees regardless. Those are very thematic to bladesmarch and enrich any experience as you're going to have a unique flavor of playing mini Prussia, which is a very good theme to associate with Bladesmarch.

Now for the Royal tree "expansion" I think it should be based around grabbing up and ceding territory to friendly kingdoms. For example:

A mission tree where we establish Corintar, Wyvenheart, and w/e best aligns in the west (probably Rogeria, as Adenica has obviously conflicts) by conquering territory and then ceding it to those states while getting historical friendships with them These ofc collapse during the consolidation of Escann, but now we have an arc that's going to push us into the age of unraveling.

I think the expansion tree as an alternative to that is mostly fine, if incredibly bland (as its just a bunch of CLAIMS, etc.,) To spice it up give us exactly what the "worry" was by having another green tide disaster nation appear and try and ♥♥♥♥ us up a few years after uniting Escann but as a requirement for forming Castonath/Black Demense.

As it stands I played the royal and finished 90% of the tree before 1500, and then had to wait around with my thumb up my butt because I was hoping there'd be more content unlocked after Corinism appears.... which there was not really much of anything (aside from the blademaster events, etc., but those happen TO you rather than something you do).

Also if we have the greentide disaster give it to us with the royal as well a few years after establishing the allied states but now everyone gets a bonus to beating back the new tide.