What it means pyrhic is that none of those, bar one, has potential to be a stealthy raider :)
Also, for what it is worth, I always know the result of betrayal against pyrhic is swift decimation of my empire. We’ve crunched the numbers, odds of winning at 1 in 14,000,605. It starts with dark hounds emerging from the mists on some border provinces. The leaders just shrug their shoulders - cowardly peasants who are imagining things bigger than what they are. Then the reports get more dire… An army appears where once there was no army. Co-ordinated strikes, bodies of the fallen a sign of their passing before disappearing again, to re-emerge elsewhere.