It would probably be easier to find a taker for Nunez if he wasn't coming off an injury-plagued season.
I think I'd rather have Nunez anyway. This isn't 2014 anymore where Tulowitzki was a dominant offensive force in the game. From 2015 thru 2018, Tulowitzki has an OPS+ of 97 and Nunez has a OPS+ of 98, so this seems like a lateral move at best.
Not to mention, Troy's desire to play 2B is not known, but I can believe he would prioritize an opportunity to play SS over it, even on a bad team...