In a panic, she ordered the Fitzgerald to turn directly into the path of the Crystal... She may well have panicked, but depending on proximity, that may have been the correct move, if executed correctly and in time. In other words, the move may have come from training, and it may merely have been inconsequential if executed too late.TFA:
Instead, Coppock ordered a move that disregarded the very basics of her training. She commanded the helmsman to gun the destroyer’s powerful engines to full speed and duck in front of the Crystal by heading left.
I don't think this abortive maneuver is well indicated in TFA's "cut-scenes", but it would never make sense as a way to avoid a collision. Unlike the situation you describe in which two ships were traveling roughly parallel courses, the courses of these ships were roughly perpendicular, with Fitzgerald's starboard side facing Crystal's port side. The way for Fitzgerald to avoid contact would have been to change speed (either faster or slower) or to steer hard to starboard while slowing in order to go behind the other vessel. The presence of other vessels might have caused problems with any of those options, but "matching" the other ship's course was likely to cause a collision. If she had enough power to clear the other ship while turning to port, she had more than enough to clear it while maintaining the current heading. Of course, she didn't have enough power to do either, at 0130.
There is no indication in TFA that Crystal was ever plotted as a separate contact from Wan Hai, even after they finally noticed Crystal. If that's the case they really were flying blind, relying on nonexistent intuition to steer through the gauntlet. It would have been surprising if any of the bridge personnel had had enough experience to simply see the right maneuvers by eye at night, which TFA seems to imply Coppock attempted to do. Perhaps the CO or XO would have had that experience, but since they were both in their cabins instead of on the bridge we'll never know...