Well, I didn't know all that! I only knew about changing envoys.
As a rule I've only favored titles upon men in the Consuls faction; due to Lucius Aemilius Barbula's being in the Military Faction and winning much success and popularity in the Pyrrhic War, I now have 40 Military senators, 26 Populists, 18 Civic senators (second consul was a Civic), 11 Religious senators, and 5 Mercantile senators. I'm aiming at keeping all power in the Military camp and eventually--is it possible?--taking over the entire senate. However, I have enough dissonance as it is. Though Barbula has become something of a legend, every magistrate and commander is a Military member--except for the Naval Prefect, and I'm grooming my golden-boy faction leader ex-tribune of soldiers, ex-governor of Magna Graecia, now Aedile for ultimate command, every diplomatic decision is quite split when it comes to the military Faction, and often up to 1/3 of them prefer Populist candidates for Consul.
Now as for converting Populists to other factions:
1. What's a safe, low enough number of Populist conviction that will probably result in switching conviction if I grant them their wish?
2. Do they always switch to the Consul's faction?