Holy bad faith interpretation batman, I believe I said Rough Divide and Burst Strike were an example i wasn't saying just boost these two skills and only these 2 skills to make up the 10%. Also in a max optimised setting, yes it would be no different to a flat increase, however in trying to reach this optimisation it will creates larger divides between those who are optimal and those who are not.
And yes that was the point about saying rough divide, someone who is optimised won't need to use the skill for mobility most of the time so it creates a toss up between optimisation and comfort, again making optimisation more engaging and rewarding.