Again, that doesn't track.
In the future trek is supposed to be, being at the top or bottom shouldn't really exist.
You get different mission profiles sure, but as we saw, personell from Cali class ships can be promoted to other ships that do high profile missions.
It doesn't make sense that SF and UFP would discriminate against a whole design class and it's crew because of the mission profiles they do, because that kind of behaviour should have been left behind in the past.
Like I said, LD took liberties in how SF behaves, and I don't like the precedent it sets.
Also having people thinking 'there will always be people on the top and bottom ' is nonsense. That's a product of existing socioeconomic system...one that doesn't exist in Trek (so the conditions to manifest the same behaviour wouldn't occur), but I guess this is something that people tend to ignore.