I think their hands were really tied when they decided to end TFA on a cliffhanger, basically having to start off where it was left off with little to no time passing.

Apparently they kept struggling with the script, because as soon as Luke showed up he took the spotlight from the new characters. So Kiri Hart actually had the idea of having Luke be the McGuffin of the story, and then finding him would be the ending of the first film.

Though the characters don’t seem to change that much between the end of 7 and the beginning of 8, so to me I don’t feel any dissonance in that regard.

I do think it would’ve been interesting to see a large First Order fleet assembled over Starkiller before jumping in different directions to invade the major systems in the galaxy. In TFA, we’re left to assume they have a fleet offscreen, which we end up seeing in TLJ. In TFA we only see a few Star Destroyers at most hovering over Starkiller.

I mean, they have had 30 years to assemble a fleet and plan their invasion down to a T, but it would’ve been nice to get a glimpse of that in TFA.