This mod is nice, but it has some MAJOR balance issues. These are some of the issues I came across while playing as Isengard:
1. Riders of Rohan are way too powerful. They come at the start of the game with three movement (!!!), 5 attack and 3 defence. There is nothing Isengard has to compete with that. The best attack rating I have access to is 3 and the best defence I can get is 2. Nevermind the insane movement speed. The worst thing about this is that the RoR aren't even that expensive compared to my units...
2. Every Ent unit. Huourns have 3 speed, ignore movement cost for all terrain and have 4 attack and 4 defence. Ents themselves have 2 movement (which ignores terrain penalty of course) 8 attack,4 defence and they enslave enemies, turning them into Huourns. Oh and they both have a strong bombard and a health bonus. This is just crazy - the Ents could attack and destroy Isengard on turn one with their starting units if they wanted. In fact these guys are just so ridiculously over-the-top, they could probably destroy every other faction in the game without producing a single unit.
3. Rangers. Invisible units with better stats than I anything I can make. Again, they are present at the start of the game and again they aren't even all that expensive. They basically wittle down my forces due to attrition, since I can't even use artillery on them to even the odds.
4. Insane production of my enemies. Rohan has 6 cities with a combined population higher than my own. So basically they can build more stuff than me. Combined with their insanely high unit stats and efficiency, this puts me at a severe disadvantage both in terms of quality AND quantity (which is really dumb since in the lore Isengard is meant to have numerical the advantage on their side).
5. Insane number of enemy factions. At the beginning of the game I find myself swamped by Arnor, the Shire and Rohan. Later on the Ents and Elves pile on as well. And there are no competent allies nearby to help me out. So basically it's 5:1 and my enemies all have better units and production than me...
6. It's too easy for Isengard to starve. 90% of it's food comes from 3 tiles, all of which are within 2-3 tiles distance of my borders. This means that a Rider of Rohan for example is able to reach any of these tiles in one turns movement and block off a third of my food supply, which inevitably causes starvation. And don't underestimate the effects of starvation - it causes me to lose any production on the turn in which it happened, and considering that nearly all of my production is centralized in Isengard this could paralyze me indefinitely if the enemy is smart/lucky..
Basically all of these balance issues place me into a situation in which I can't win. I did come up with a strategy in which I was able to survive a very long time, however the constant attrition from fighting vastly superior enemy forces meant that I was doomed to die a slow death no matter what I did. Also the One Ring mechanic is flawed, since Frodo (or whatever invisible unit was carrying the ring) constantly suicided himself against me in almost all of the games I played.