To be honest I get the feeling that the Garlean occupiers intentionally put the foot down. Garlemald would have had a lot of experience subjugating and assimilating populations. Even taking Gaius's world view into consideration, the Garlean's treatment of the locals is rather counter intuitive when it comes to driving people to pull themselves up by their bootstraps. They take most of the abled bodied people for their armies leaving the remaining people with a lack of effective labour to look to new options, they demand the locals deal with 'local pests but then brutalise people for carrying weapons by accusing them of being insurgents. If Gaius's goal was for people to earn their place, he created an environment that discouraged it.
Honestly the most sense to me is the treatement of Ala Mhigo to be one of 'breaking in' the population. Crush them till all resistance has been squeezed out, and then when they are just miserable and just trying to survive to the next day, offer them succor so they feel greatful to you. It would make a lot of sense and as unethical as it is, it would probably be effective. Again I just point to Ala Ghara for an example. Just the act of stopping the soldiers abusing the locals earned loyalty and gratitude.