Well it was easy since the travel from trimbar to Avamar was the 2 days, with the capital city in the middle of the road to 1 fully day.
And a small (5k-7kCS) asrmy stationed on Parm to keep SOA t bay on Caqueta and Csopa, i recall the fartest SOA manage to go into Sirion's land was Oslamar.
I really loved the war against Sirion it required strategy and not power, the reason i love more on BM. Power battles are just be silent, follow orders like a dummy puppet, attack here, there and profit!