The interesting thing is, at the beginning of "Omega Glory" no reason whatsoever is give for why our heroes approach the planet Omega IV. They find the Exeter
in orbit, yes, but it's made clear that this was a surprise, and they definitely weren't looking for her - they didn't even know anything was wrong with her, and didn't believe she would still be in this part of space after having visited the Omega system half a year earlier. "Requiem" in turn ends with the ship setting a course to... Somewhere. We never learn where, we just hear the heading spelled out.
The two episodes could really play back to back: Kirk goes to Omega to find rhyetalyn, has a brief adventure involving Flint, and then decides to have a look around. He then stumbles onto Tracy on the next planet. That wouldn't solve the Galloway problem, because "Requiem" very much has a stardate that places it before "Turnabout Intruder", but it would be an interesting dramatic combination. Kirk's crew has just recovered from a horrible disease, and now they encounter Tracy who has lost his own crew to another horrible disease...