I've got a few more suggestions, two of which have probably been covered innumerable times since they're about Haradrim/Easterlings but I figured that since they're smaller tweaks, they'd be better suited here so let's get started!
More Tribute Camps bring more reinforcementsSauron's Influence on the Tribute Camps originally increased the amount of Haradrim/Easterling units you could summon upon activating the power but this sadly got replaced with unit upgrades. Though I acknowledge that orcs are the backbone of Mordor's forces, I still believe that evil men should have a little more of a presence so what if we could bring in more of them with each summon if we had more Tribute Camps? If you have 3 Tribute Camps the amount of reinforcement's you'd get will be doubled and if you have 6 or more you'd get three times as many as you'd normally get with just one, to balance it you'd have to have 240 free Command Points to double down and 350 Command Points to triple down on your Easterling buddies (600 and 900 for your Harad buddies). It isn't the most ideal solution but if evil men
must only be available by summoning and
must have their powers on such a high cooldown, it'd be nice if we could get more a bang for such a hefty buck.
Reinforcement tweakingAdding on to the previous suggestion, I'd like the Haradrim power tweaked so we can actually get some dang archers to go with the Mumakil, even if they have to walk into the map and be moved on that way. After all Haradrim were renowned archers in both movie and book and not including them is like making a Jaws movie and forgetting to put the shark in. Having the spear throwers would also be nice but having them along with the archers
and the mumakil
and the horsemen might be a bit too much. As for the Easterling power, I'd like to see some Corsairs along with the pikemen and warriors - It's not the most fitting place for them since Umbar is more south than east but if we can have access to their ships surely we should be able to have some way to bring the brigands onto dry land for the fun.
Morgul CaptainsThis one's more of a spitball but I've always wanted to see some wargs for Mordor to call their own. Them being a standard cavalry unit's out of the question since that's supposed to be a weakness of theirs but if the Iron Hills faction could get a few Ram riders as scouting units that can be upgraded into battalions at a high enough level, maybe Mordor could get Warg Riders in a manner similar to this? It isn't that high on the priority list and the faction can get by without them just fine but it'd be nice to have, them being Morgul Captains would fit well with Gothmog since he currently has the only Warg in seemingly all of Mordor.