I suspect for most of the rest of the first half (up to ep 26), characters like Graham, Patrick, Sergei and Soma (and possibly Ali) will be pushed into the shade a bit by the Trinity. If the OP is any guide, then we should probably see a show-down battle between the new vs old Meisters around eps 24-26.
Currently, I'd expect the 3 siblings to be killed. (Will Setsuna kill Nena?). It would likely end up being a close call, with the 4 "main" Gundams being heavily damaged. Maybe enough that the 3 powers will intervene at the end and grab some CB tech from the destroyed Thrones. (An interesting possibility is that one or more of the Throne pilots could survive and turn up later as a tool of one of the 3 powers looking for revenge against CB). Also, if the 4 are *seriously* damaged then CB wouldn't be able to do any interventions for a while, leading to a natural break.
I see this is a stepping stone for the 4 "main" Meisters to grow both as characters and as pilots. They haven't exactly be lauded for their skills by others in the series, but they'll definitely have to improve if they want to defeat the Thrones.
As a side-note: the attitude of the Trinity towards using Gundams to intervene seems quite close to Alejandro's. Co-incidence?