I would consider it as well because while Dame/CJ are a very good offensive backcourt, they are so out of balance because defensively they can give up even more than they score. If Crabbe could step in to be a starter and give you 17-18 points will getting more rebounds and playing better defense, I think you have to look at that. Now you'll need another play-maker because CJ is one of the few that can take that pressure off of Dame. Montero has the skills but not the experience and Aminu is still an adventure almost every time he puts the ball on the floor.
Getting a nice (bigger) combo guard to come off the bench behind Dame/Crabbe is your could get something like Okafor+ for CJ might be a heck of a deal. CJ is worth a lot because he is a 20 ppg scorer on a minuscule contract for another year and then possibly team control for even another year after that.
Portland's back court needs to play defense. Curry/Thompson, Westbrook/Olidipo, even Wiggins/Dunn/Rubio all can score and all are much better defensively than Dame/CJ. 2 of those 3 are exactly who you will have to go through to make more than a small dent in the playoffs.