I'd have to say no on this. Crabrawler has a pretty great Attack stat for an early game Pokemon, and it's moveset is pretty decent, but it's held back by one thing: it's evolution method. Crabrawler evolves by leveling up on Mount Lanakila, which can't be accessed until literally right before facing the Elite 4, which means it'll be stuck as a Crabrawler until then. And it's stats aren't really the best for it; it's Attack, while good to start with, will quickly get dwarfed by your other Pokemon as they get stronger, and the rest of it's stats, while ranging from meh to decent starting out, will quickly become abysmal as you face stronger and stronger foes. The only way you can really get around this is to do what I did and trade your Crabrawler to someone who already has access to Mount Lanakila so they can evolve it for you, but that's only if you really want that Crabrawler on your team. Besides, there are three other Fighting types (Mankey, Machop, and Makuhita) that you can get on Melemele, and another one (Stufful) that you can get later on on Akala that are less cumbersome to evolve. Whether they're good later on or not, I don't know, but they are alternative Fighting type options.
Anyway, TL;DR: Don't go with Crabrawler unless you really want to.
