Hi again!
First of all, thx for your responses. We play in a very odd way because my friend wanted to go to a championship with rare rules too: 300 points and 25 models maximum. I think Dark side is a bit unbalanced because of that too (I can't overwhelm them with more models because we have the same number!), but I'm not sure because I'm a bit noob
On the other hand, I use to play Minas Morgul because I love Black Numenoreans. I see that Morannon orcs are much efficient warriors, but then I had to drop the Nazgul that works really good holding great Light warriors. However, because I can only ally with another force, I will lhave to drop it if I want to fight with Morannon ones (another alliance not allowed, damn Nazgul separated army list). Anyway. I understand why Uruk-Hai armies are very popular, they have awesome stats and I think they are one of the most efficient Dark armies (Saruman with one cast spell free is wonderful thinking as a RingWraith lover
).
Overall, I'll try antoher things and I'll think about dropping Numenoreans if I want to play in a more competitive way. Perhaps Morannon orcs with a drum to avoid some bow fire until they reach combat.
Thank you for your advices!