One of the problems i noticed with the balancing, which tremendously favoured Snowballing, is that faction growth is exponential via the defection system. On my first campaign, i joined the Vlandians early on and we were relatively balanced out. That is until the battanians came knocking with a 1.2k army and we lost Sargot to them.
We lost a city via war.
Then most clans started defecting Vlandia to join Battania/Northern Empire. We lost a city via war, but we lost 2 cities and countless castles via defections. And so, battania now fielded TWO 1.2k armies, one of which was mostly compromised of Vlandian defectors.
My point is, not only do factions have a horrible time trying to get back on their feet (recruiting, looters, priorities, etc.) but the winning faction just keeps getting bigger and bigger and able to fight many more wars at the same time. The second they start capturing cities and recruiting defectors, there's literally no way of stopping them.