Yes, I wonder what cards Caerwyn has up her sleeve as Astrum seems to be far stronger then Caerwyn alone already. Madina will have trouble contributing to the War due the long travel times, assuming Terran allows them passage through her lands. Fissoa is currently already in a War with the Lurians. Terran also has a large SA element in it and I'm not sure they will be taking an active role, especially with Barca needing their attention for now. D'Hara has elements of SA and VE in her Realm and has made no move to change her stance of neutrality for this conflict.
So that means Caerwyn, Averoth and Madina, with the latter being obstructed by her long travel times. Anyway, I'll surely be watching this War, as it does seem very interesting.