In Radmar’s case, I would bet on INT -1. INT 0 is supposed to be average and Radmar really is an idiot.
@Ramidel Thank you so much 
for linking the Girl Genius web comic. I had never heard of it and I enjoyed reading through all 15 years of it!
Good point.
My MC will have to be as tactful as is possible with CHA 1 when meeting Cabel because my MC thinks they were all fools. Timing the rebellion for when the armed retainers of nobles were away indicates to my MC that they viewed those armed retainers as a significant part of the Hegemony’s military potential. The old Shayardene monarchy probably had fielded much larger forces likely with trained wisards (though without aetherial blood) and the old royal house still lost. Thinking to beat the Hegemony with a smaller force than that without wisards and aetherial blood of their own was tantamount to mass suicide. Horion mentioned that there are approximately 20 million Shayardene helots. A government that can control 20 million people is not going to feel seriously threatened by 10 thousand rebels. The equivalent of the police force (in this case alastors and kryptasts) probably numbers more than 10 thousand already.
My MC intends something along the lines of the levée en masse from the French Revolution of 1789. In the words of Edmond Louis Alexis Dubois-Crancé:
And so I say that in a nation which seeks to be free but which is surrounded by powerful neighbours and riddled with secret, festering factions, every citizen should be as soldier and every soldier should be a citizen, if France does not wish to be utterly obliterated.
@Havenstone My INT 2 MC has enthusiastically embraced literacy lessons for the rebellion not because the MC loves reading (though that is true) but for the entirely practical reason that the rebellion needs wisards of its own. So my MC intends a levée en masse for wisardry. Going with the rough estimate that a literate helot is one in a thousand (INT 2 helots see this estimate), that would mean there are approximately 20 thousand literate helots. If even 10 percent of those can be trained into wisards then 2 thousand rebel wisards is something for the Hegemony to fear even without aetherial blood. With the ability to make aetherial blood (which my MC is headed into the Xaos lands to study) and with more helots regularly being trained in literacy and the fundamentals of wisardry, that is the sort of force that could topple the Hegemony and drive off foreign encroachment.
As far as what the MC’s rebellion is hoping to achieve politically, another good example would be the Turkish War of Indepedence. A militantly secular government under Mustafa Kemal Atatürk repelled foreign invasion and rose to replace the Ottoman Empire that had been ruled by the Sultan who simultaneously held the religious position of Caliph. The fact that literacy rates in the Hegemony are so low for helots likely means that literacy rates for the total population are horrible. However like the Republic of Turkey, which increased literacy from 9% in 1923 to 33% in 1938, for better or worse the MC will be able to forge an education system almost from scratch. So my MC intends to keep a vigilant watch upon the curriculum and in addition to the fundamentals of wisardry, books about concepts the rebellion’s ideology embraces will be required reading.
My MC would prefer having the capital surrounded by people that would share the rebellion’s ideology even if it means cold weather. On the subject of wintry conditions, if the new state needs a coat of arms eventually, so help me my MC is going to insist on a mule being prominently displayed as one of the things that made the rebellion possible.