The catch here is the legal right to work in those countries, because even if you do join a flight school with a partnership then you need the legal right to work and live. In addition, joining a flight school is supposed to be a 0 to flight hour task, so I don't think you can just transfer with ATPL credits and a PPL without performing rigorous transfer procedures. Each school would like to teach you their way, the way of the airline they're contracted with.
The only one I know of that doesn't require a legal right to live and work in the country is Air Arabia's Alpha Aviation Academy in the UAE. Although the MPL program with them is from 0 hours to flight so your ATPL credits and PPL wouldn't have an effect and also costs around $100,000.