Sounds interesting. I think you waited quite late to attack. I find a block of 25 soldiers (the ones you start with + recruited principes) can kill 30 (easy) to 50 (sometimes) enemy without problems. I would have probably struck out a couple of times, returned to re-arm then continued as you did.
Why not a bunch of lightning rings and combine your comunion strategy with wrathfull skies? There might be a good reason for this me = noob so I don't know
Also, what -exactly- is your standard communion army form? How many of each unit? Any screening units?
Ta!
Calistas