Or perhaps take an army with Elendel, Isildor, Arathorn and Aragorn oh and Malbeth and Eorl the young just in case we left any periods of middle earth history out.
All I hear on these forums is that Numenorians and to a lesser extent high elves suck due to a lack of options. High elves definately don't suck but they have access to more heroes and can rock the best of fight value and armour.
Numenorians do have very limited options, those options are not bad but its all they have available. Their armour is moderate, the fight value higher than average. They bring more numbers than the more elite armies or at least bring a fair number of warriors even if you do take both of their named heroes.
Both named heroes have great stat lines, low on fate points but brilliant armour to make up for it.
If you want a numenorian force, go for it. If you want a more powerful army, perhaps look at ones that have more options, though numenorians should be a solid enough force if used well.
Allying high elves in also adds in a lot of variety and is probably a more powerful combination than Numenor on its own.