Let's talk aliens.

[Treewyrm]

The second, which has not been discussed as much, is to humanize the nomad. The nomad (and borg) serve as such effective enemies because they are purely evil. There is no reasoning, no peace, no compromise. It also serves as a hinderance to plot development. That is why they don't serve as a primary enemy for most factions. To humanize the enemy serves to give it unique personalities and characteristics to consider and enjoy. In short it deepens the quality of the plot.

You were quite right by saying you don't quite understand what they are. Because you really don't by considering borg and nomads similar to each other in this way. If you want purely evil beings - look for phantoms. Nomads are simply alien, different, they're agnostic in terms of morale, therefore "evil"/"good" stamps are not applicable to them unless you're in-character, but here we are talking outside of that. There are (and were) unique characters and personalities of those allied to them by their own will, individuals who had greater knowledge of what "associates" are. So who is missing the point here really? Putting all eggs into one basket, that is both borg and nomads, is hindrance to the story rather than filling special niche. Just think outside of ST TNG box without references to it.

p.s. Replying to your posts before that one: yes, Discovery does actually remove/replace ships borrowed from other fictional universes from version to version to make each new ship added into the mod genuine.