Well, you are more likely to win with the Mordor list, as only Khamul and the Mumaks redeem you.
A few things you need to know about soe of the Fallen Reakms units:
1. Haradrim infantry with bows are good, they're dreadful without them, compare them to the WoMT your opponnet'll field and you'll see what I mean. They are usable without bows as long as, and only if, you permanently keep Khamul in them.
2. Corsair are the same cost and are even worse. If 6 comps of Orcs w shields including 3 comps in support fight 6 comps of Corsairs w shields includiong 3 in support, the fight's be even, only Corsair cost an extra 10pts per company (more than WoMT!
), I'd only ever take them with Dalamyr's Battlehost as they become Beserk.
3. Eastetrlings are better in formations of 4 comps with Dragon Knights and Kataphrakts are rarely worth it.
4. Centring your infantry around Easterlings would be a good idea (maybe Black Numenoreans or Khandish instead/as well, but they're metal) 2 or 3 blocks of 4 should do, woth Harad archers, mumakil, heroes and Harad Raiders.
So, in short, since your Mordor's already painted, and your troops aren't way too overcosted, you may be better of woth them.