I'd imagine you're right. I don't think the Order had the resources to legitimately hold the galaxy, they probably had their hands full just keeping trade routes contained, maybe keeping a presence over certain noteworthy planets. I mean, they were held on the fringes of the outer rim and a small group of resistance fighters were enough to keep them there (until the Order fired up starkiller base). There's no way they had enough ships to maintain a presence across the galaxy.