Case in point: When Eponllyn was migrating north to flee the ice advance, we ordered all of our people to bring siege engines in case something happened and we needed them. We didn't plan on needing them, but you never know. When we got to Oligarch and started talking to the ruler of Westmoor, he insisted that we came north specifically to attack them, because we ordered all of our people to bring siege engines. WTF?! How does the ruler of a potentially hostile foreign realm know that our army was ordered to bring siege engines with them?
Because a couple of Eponllyn nobles came to Westmoor and joined us because they didn't agree with Eponllyn's hostile attitude to the Southern Alliance, and Westmoor in particular. They said, "Hey, Eponllyn is planning to attack Westmoor". Combined with some other diplomatic stuff that was going on, it was more than enough to persuade Thomas and others that Eponllyn had hostile intent.
There was no 'spying' or "sharing realm messages with hostile foreign powers". Just an old fashioned defection by dissidents.
