Tens of thousands of soldiers at the very least hundreds of thousands are the most likely and even millions are possible. Remember that Shayard alone has a population of 20 million + people, since if Horion is right then Shayard alone has about 20 million helots, add to that the yeoman (including free lower class urbanites), the merchants and the nobles & priests. Assuming that helots are about 50% of the population that would give a population in Shayard of about 40 million.
Shayard is likely to be either the most or second-most populous of the provinces, but I think between 100 to 120 million people for all the provinces of the Hegemony, including Karagond itself together might just be a reasonable estimate.
If even 1% of that figure is the dedicated military, discounting Alastors, private guards and other shady enforcement agencies that means the Hegemony reliably has 1 million + soldiers.
Of course a lot of them are stuck guarding the borders and other vital targets, but that still leaves plenty to combat our rebellion.
If that all holds true one can certainly get Sybla’s hesitation.
What do you think @cascat07 ?