I kinda think you’re mostly right but have the roles reversed. Yes, Frost and Martinez were the constants but I think they were the constants that kept us just that close and it was the other things (special teams, OL, kicking, coaching) that prevented getting over the hump in so many games.
I have no idea what will happen this year. I’m with runningblind, I have to see it on the field before I’ll believe any of it but it does appear they’ve addressed a lot of the deficiencies and made additions/improvements just about everywhere. Frost is the remaining common denominator. This year is it, sink or swim.