I like the idea,really.But i think that the team just doesn't want to work on arnor anymore
After aragorn is crowned king,all unit production buildings can be upgraded with Arnor upgrade(cost 500).Every building must be upgraded to recruit them,this works like normal building level upgrades.
I thought a way to unite the concepts,too.After aragorn is crowned king,all the modifies to fort upgrades and buildings are applied.However,you have to purchase upgrades even though you did before.As men stonework will cost 2000,while numenor stonework 3000,fire arrows cost 1500,while numenor arrows 2500 ecc..
I think,anyway,that aragorn(3500) should be only recruited from the white tower after you captured a inn.From the inn you can recruit Strider for 2000.
I think that aragorn is simply too hard to obtain,he is the strongest hero of the faction,he should be recruitable even though you don't have any inn.There are maps where there are no inns,or where there is only one.Capturing that single inn makes you gain the upper hand with one click,this is simply imba.
The last concept is about trebuchets.They should,first of all,be bigger.In the films they were huge,in-game they are ridicolously smart.
Since bfme1 trebuchets could be upgraded with fire stones.But gondorians never used flaming projectiles,they used rocks and,in case,pieces of numenor bastions.
The flaming stone upgrade should be replaced by numenor rocks upgrade(this is the default upgrade,not related to arnor
).The siege damage is doubled,while there's no longer any fire damage.