The Airbus A220 will be chosen for regional aircraft. They usually can support 100-150 passengers which will be more sufficient to transport people to the region of the country they wish to go to. Regional Aircrafts will connect with the Kaldus International Airport, and any neighboring regional airports if there is enough demand for them. Each regional airport will have several of regional aircraft with backups in case something was to happen with the first choice.
Airbus will be chosen for simplicity to the pilots, and for cost effectiveness. If there was multiple aircraft being purchased from one company, that company might reduce the cost per aircraft to make the price reasonable. And a purchase with Airbus is one purchase not made with Boeing, or any other manufacturers. Since each airport will have several of aircraft, they will be able to interconnect to other regional airports, and to the international airport.