I'm not sure how I feel about the Nemesis system. It's a fantastic idea, but it seems to me that it's massively overused. What I mean by that is that you go through so many of these guys that none of them ever really ends up feeling special and memorable. The fact that the game is very easy doesn't exactly help.
What the game's really missing, IMO, are actual bosses. The Nemesis system was supposed to dynamically make bosses for you, but because it makes so many of them and the game is so easy they end up feeling like regular enemies that you kill without really paying attention to them. To me it feels like normal uruks are just mobile hit streak point dispensers that die if you so much as sneeze vaguely in their direction, the Nemesis captains and warchiefs are regular enemies, and the bosses just aren't there.
That Talon fight where the game tells you to kill your nemesis? It presented me with an uruk that I'd never seen before. Why? Well because captains and warchiefs ceased being able to kill me some ten or fifteen hours before that, and ever since that point any and every captain or warchief that I met died in the encounter. Perhaps the devs should have just made them more powerful across the board, or perhaps there should have been a tier above the warchiefs for a single uruk that would make that uruk super-powerful to make sure he can actually pose a threat and act as your nemesis. Perhaps the game should have been a bit more scripted. Rather than pick an uruk to be your nemesis in the fight at the time of the fight, the game could have picked an uruk to be your nemesis early on, perhaps based on him being able to kill you, and then simply made sure that you weren't able to kill him. Or something.