Julien has a higher OBP with significantly more power than Arraez did in the minors, plus he's better defensively. They also have Lewis, Kirilloff, Miranda, and Lee to figure out long term in the IF with Correa, and even if Buxton is going to start playing more in CF, he's still going to DH plenty.
Once again you're trying to degrade Lopez because he's had a couple of tougher starts lately. It's a long season and everyone goes through ups and downs. Over the last month he's still been better than Gerrit Cole, and about the same as Ohtani. I'm sure you wouldn't trade Arraez for them either...