Well, it depends, do you ever plan on using Resistance? If not, then I guess you can skip. But they're really, really good. And all the characters are pretty easy farms--except Rose and Holdo--so you can build the team pretty quickly.
I say go for it, personally.
If you plan on using Rey as a splash character (ie: No other Resistance, just her) then her unique that gives a 40% chance to cleanse any debuffs on her after they're applied is still worth it.