It's a horrible system and needs to be removed, when players tier up they should get increased resource rate, this is to replace escalation phases.
Though the best economy system is that of Firestorm over Kaurava.
Tiering up giving a resource boost would snowball massively.
The way I handled it with my mod, Exodus, was to make upgrading nodes more effective. The advantage of this is that upgraded nodes can be captured by your opponent and they can benefit from the upgrade. Comparatively Escalation Phases were toned down.
imo the economy design is the single greatest design flaw of DoW3. Doesn't help that they haphazardly messed with it by reducing power income which really screwed the game up too.
I agree about your choice in your mod as I continue to support the tier up resource increase. Both need to happen while removing escalation phases. Besides for resources u can attack shield generators and turrets.