My suggestion is to reduce the physical size of the AEON T2 Shield Generator: Shield of Light.
I don't suggest any other changes to the building. Keep the shield radius, cost, lack of T3 upgrade and everything else the same.
WHY:
Currently, the building has two critical issues.
Firstly, the shield radius is simply too small for the current building size. By decreasing the size of the building (I recommend from a 6x6 to a 4x4), but leaving the radius the same, it can now appropriately cover buildings like other factions T2 Shield Generators by moving the center closer. Players could still use it as they always have if they wish, but the reduced size adds options.
Second, The fact that the T2 Shield Generator cannot upgrade to the T3 version is a key limitation of the faction, requiring higher micro and inefficiencies. By making these two buildings have distinct sizes, and thus different potential locations for construction, the overlapping of the bubbles becomes a viable option.
This solution makes in-universe sense. The shield generator is an efficient and cheap building, but lacks the upgrade feature for no apparent reason. Being different sizes is a good reason, and expresses the faction's differences more elegantly.
(If someone else has suggested this before, I apologize. I have not looked through the forums extensively, but most posts are simply asking for the T2->T3 upgrade. I prefer to accent the differences between the factions, not minimize them.)