With the new book of spells, Mordor turned out to be very good and balanced. I have only three comments:
Khamul has a lot of life and armor. Even dwarves with their mithril armor have less armor, because of this, Khamul is an extremely good killer hero (even too much). If you slightly lower his armor everything will fall into place. And the second question: is it possible to replace the call of the Easterlings with the Castellans. (After all, he is Lieutenant Dol Guldur and has nothing to do with the Easterling, despite being once their leader.)
Necromancer - he provides unique and powerful abilities for support and in fact wanted to offer only two small additions. In 3.8.1. I really liked the ability to double. Maybe when getting the ability from the spellbook "Deadly Servants" when he will use the escape ability, a double will stay in place!?. In fiery form, too, there is a small problem. Even at level 10, he must spin very close to his enemies, which means he dies very quickly, that if you slightly increase the radius of defeat by fire ???.
Well, the most painful topic is Gorthaur. Personally, I never buy this ability. The reason is one: the Necromancer receives very little bonus. The only thing I really like about Gorthaur is Anattar. (Beautifully, canonically, effectively and uniquely). I do not know who of the players uses the form of a vampire or a wolf? I think they are very weak. I'll give an example: You need a Necromancer + 25 points to open the ability, but in the end! Valkulak is weaker than any hero the enemy killer! And the standard abilities of Gothaour are very boring and weak. Only from the blade of destiny is there a benefit. And I kept thinking about the bottom: Perhaps instead of invoking the fortress Тол-В-Gaurhoth Gorthaur would strengthen the tower of the fortress / camp, because Barad Dur is a very significant one, and it would be interesting to give Gorthaur the opportunity to strengthen his main fortress the second and third era !?
Sorry for the criticism and comments, just wanted to give some back link!