Power differentials really isn't that big of an issue for competent writers.
Ideally, a writer wants have stories where characters of different power-levels and sets can be engaged. Where it comes to "OL" characters ideally you want them to have levels and variations where they can be useful in a team setting without having to bust out the OL feats (at a minimum) or overshadow the other members. Iceman, Jean and Storm do work in that capacity...where they employ their skill-sets in a range of feats. OL feats are usually reserved for huge moments like terraforming Mars.
Of the 14 Omegas Hickman listed...Only Jean (solo) Storm (solo) Magneto (XM) Quentin (XM) are on active duty so far in the Brevoort Era. Iceman, Hope, Elixir, Legion are still to be placed/accounted for.