Well done terrain, even so its a bit on the smaller side, the way the islands are forrmed make it pretty well scaled at least for infantry operations. Also good to see that some microterrain was added so its not completely flat.

There are a few things that could be improved imo.

1.) The military base seems a bit small, could be 2-3 times bigger with some more quarters to house soldiers but also maybe some storage buildings.
2.) The military base could need a small harbor nearby, so goods can also be delivered by sea, but also to start patrols by boat.
3.) Villages all are pretty small, at least one bigger would be interesting not at least as point of interest, but also to add more different looking places.
4.) Is a nice looking place without any bigger changes done by man, no way i believe that. Maybe add a place where the trees are already cut with either for example a fish processing plant or a hotel complex in the process being constructed.

So you could have the cut trees laying around ready to be picked up, all kind of building machinery and material being ready to be processed to create the buildings etc.,
5.) Have some small agriculture near the civilian locations, maybe only in form of some gardens, so the population can provide for themself. It also adds some more useful detail to make it look more like a real place.

Maybe also some fencing for some farm animal near the villages.