Wondering that I cannot find this question, so I ask:

During a big part of the movie (several hours in universe) a small fleet of rebel ships is followed by a fleet of huge first order ships.
It is said that the big ships cannot catch up, to the smaller rebel ships, but have longer lasting fuel, so in the end will catch up when the smaller ships run out of fuel.
My impression was, that the distance between the fleet was constant all the time (they could see each other). Even in star wars physics that does not make any sense. There are (regardless of real world physics) just two possibilities:

1. The rebel ships are significant faster. In this case the distance between the fleets should increase and over time exceed sight distance. (Perhaps enable them to esacape?)

2. The rebel ships are barely faster, explaining the more or less constant distance. In this case the question is, how they were able to reach a safe distance in the first place.

Also I cannot remember correctly the explanation why they cannot user their tie fighters. Something like they cannot support them over the "vast" (sight) distance.

Of course in real world physics the whole situation is ridiculous. But can anybody make sense of it even in weird star wars physics? And feel free to also make sense to other nonsensical aspects of the situation I didn't mention if you like. (For example that other ships are able to leave and rejoin the fleets without being noticed or harmed)

Edit:

Perhaps more concrete:

Did I miss anything that explains the situation in the movie?