I would personally be switching between all 3 of them. I get bored easily if I stay in one job for too long, so I often switch between WHM, NIN, MNK, DNC, and RDM to keep things fun for me. Though, since my static already has its 2 healers and a DNC, I'm limited to NIN and MNK for my switcheroos to not cause any party comp troubles. I enjoy playing all 5 of them, so why should I, or you for that matter, limit myself to just 1 for savage content? Since all 3 of your prefered jobs are ranged DPS, switching between them won't mess up your party comp. Plus, mastering multiple jobs makes you a more flexible player overall, and gives you a better understanding of your teammate's jobs, which leads to better teamwork. So, why limit yourself to just 1 when you clearly enjoy all 3 of them so much that you just can't pick one single job to main?