........ but I'd question why not use a beech 200 with high density
The usual reason - on average the Beech 200 is up to three times the capital cost of an Aero Commander 690/695.
Fagali’i: 670 meters
Maota: "The airport has a short runway which can only handle Twin Otters and other small passenger aircraft."
Asau: "There is only one rigid and roughly surfaced runway. Only Twin Otter and Britten-Norman Islander planes can land and take off this small airport, generally because the runway and tarmac cannot handle any other larger and heavier aircraft."
And they intend operating Twin Commanders in Islander and Twin Otter territory?