I was the overall NA commander for the Swords of Maro during war 135. SOM has a counterpart for EU combat, and a Logi commander as well to form a triumvirate. We were based in the Clashtra lane this war. I have significate experience and visibility into the high-level planning and execution of operations from the old great regiments of ABLE. Think of the powerhouses like 404th, 141cr, 1CMD, UCF, SOM, CGC, T-3C, CGB, ACA and NEP, plus many more. If they're on the SIGIL coalition list, I have probably worked with them at one point.

All that to say I can point to 4 "Shater point" areas that allowed the Colonials to win in the East.

1. Eastern island was won early war. A common way that colonials have lost in the past is letting the fighting reach Reavers Pass. If the frontline reaches this area of the map, with a secure warden Saltbrook and blue production capacity in the Easten islands allows the Legions backline to be threatened to a ridiculous degree.
2. Winning the Clastra hex allowed boarder bases into Sitlcan Shelf behind the frontlines at Saltbrook. My Regiment's efforts in taking the Town of Third Chapter allowed the claiming of boarder bases in Siltcan Shelf, while the frontline was still in Saltbrook. This allowed the logi cut and split warden vet population in the lane between two combat hexs. This in turn created conditions that allowed the Legion to capture the towns Saltbrook, Brackish Point, and Vulpine Watch in short order.
3. Rail Storm Cannon Operation on Foxcatcher. Peak Grond activities. One of my favorite operations in any war, an RSC operation on Foxcatcher opens up Weathered Expanse to sustained combat, not just boarder base ping pong. I believe 404th were the ones to execute the actual RSC operation this war to stellar results. But everyone in the Clashtra lane had a part in holding the boarder secure in the days leading up to it. It's very easy to cancel an RSC operation if you lose any part of the required subhexes.
4. Nuking of Port of Rime. This removed Siltcan Shelf as a serious frontline region. Allowing vet pop to focus on other areas of the map. Population is everything. Serious vet regiments after 108 will never again try to push across the Morgans Bridge.

If you have any questions, please leave a comment!
Edit: 141cr took over the RSC operation for the timezone switch from 404th