What could be done in TLJ? Make their flagship… smaller? Spell this out in the crawl?
Most likely, it woulds have to be something done in the crawl.
I always interpreted the First Order as being analogous to Daesh in the way the Empire was analogous to the Nazis. They’re a small group who nobody took seriously because they assumed there was no way they could sieze so much territory so quickly, and then, they took over by siezing so much territory really quickly. My own edit of TLJ tries to evoke this in the crawl as so:
The FIRST ORDER reigns. The New Republic has been decimated, and in this state of galactic confusion, Supreme Leader Snoke’s armies have seized key territories and taken military control of the galaxy.
Only General Leia Organa’s band of RESISTANCE fighters stand against the rising tyranny, certain that Jedi Master Luke Skywalker will return and restore a spark of hope to the fight.
But the Resistance has been exposed. As the First Order speeds toward their rebel base, the brave heroes mount a desperate escape…