the one power strengths, heres a interesting thought, what if the reason some are weaker generally is because they have, or because they were so weak, have one ultimate talent developed, or type of skill, where as higher strengths goes with less ultimate talents in one area and more spread out across several of the powers but less honed for the most part

the female channeler with shields, has a very specific type of channeling skill, that probably worsens a lot of her potential with other types of techniques, sort of like each person is a paint brush, made with different types of material, and sizes of brush, and shaping of said brush, some people are honed for a specific type of paint like acrylic or water colors and excel at specific tasks, others are more or less closer to a jack of all trades, and depending on their type of brush and bristling, are sometimes even very excellent at one or several of their jack of all trade stuff.