You are entitled to your opinion of course, however...I can for the life of me not comprehend how you think factions like Isengard and Mordor, Gondor and Rohan are similar.
Of course, if you think abysmally critical, then yes, all factions have similarities. Similarities such as: Getting forged blades, banner carriers, heavy armour, ''spamming'' heroes and units etc.
These are the core mechanics of the game and the mod. You're supposed to ''spam'' units with every faction, upgrade them, make a standing army and keep it alive.
What Edain team, I feel, did very well thus far, is distinguishing these specific features in timing, costs and visuals among the factions. Rohan being cavalry specific, Isengard being a lategame upgradable army, Mordor being a specialist faction entirely tied to Sauron for late-game and some kind of single-player element to it (they remind me of the Wehrmacht from VCOH), Dwarves being as stubborn and tanky as ever and also a lot about manipulating gold and do not forget the tunneling mechanic, Gondor being, what I personally think, a solid-overall faction with good early-game, mid-game and late-game, but nothing to excel at perhaps apart from Heroes and beefing buildings and protecting them(?). Someone probably needs to correct me on Gondor, I haven't played them that much yet.
The fact that Angmar will be the only evil faction to get walls are exactly the kind of details of which I speak and I think you are aware of this. I fail to understand how one cannot see these seemingly small differences, even though they are very significant for every faction and the gameplay experience overall.
I would tell you to play more competitive 1v1s judging from the Isengard should have walls argument, but I won't go there for now.
Nothing personal of course and I apologise in advance for my reply if I seemed irked or if you find it offensive, but I'd personally find it a little rude to call the hard work Edain team put into Isengard, Mordor, Rohan and Gondor samey (if it was my work anyway).
Kind regards.