Currently the achievement is extremely cool, one of the mechanics I like the most in this mod, but it has some problems ... But I will try to correct them.
Problems:The strength of the conquest of each faction is different, as Mevans placed only the units of the main faction / affiliated to it to appear (Gondor and Ranges of Ithilien for example), because of this appear uruks in the conquest of Mordor, golden easterlings in the conquest of Rhun, meaning elite units appearing in the conquest, but other factions like Gondor do not have strong units in the main faction only in the sub-factions.
Suggestion: When you reach 500 alignment you could choose which sub-faction would help you, from that moment when you select a sub-faction, 4/4 of the conquest you earned 1/4 would be for the sub-faction you chose.
The units hired from this sub-faction instead of giving you 1/4 of the conquest they would give you 2/4 of the achievement (Example: A Ranger of ithilien killed an orc in Gondor and earned him 0.25 points, but you had asked for help from dol amroth and when a man-at-arms killed an orc you earned 0.50 conquest points).
Do you remember that I said that 1/4 of the conquest you won would be for the sub-faction? Then this 1/4 of the sub-faction will cause soldiers from that sub-faction to appear (Example: If you asked for help to Lossarnach, Lossarnach axeman would appear).