Yes, he would be worth a look and here is why.
Fitz is year to year. We have no idea if he will hold on to make a SB run with this group, or if he will decide to give it his all this year and fade off into the sunset. When he retires, it leaves a MASSIVE gap in our WR room because we can't draft them for crap. Butler is already gone. Isabella looks to be quickly heading to bust-town, and KeSean is a depth guy at best.
Kirk has been ok...not a star by any means, and he is only under contract for 1 more year. A lot of people, myself included, think he would work best as a slot WR.
If you were able to get Robinson and keep him beyond this year, you make Hopkins that much more valuable for the life of the massive contract he now has. Robinson would be an awesome #2, and at 27 should still have some prime years left.
Why its hard is that our WR room looks pretty solid and rather full right now. The problem happens if we end up having Fitz retire in the offseason, and we end up cutting Isabella...and Kirk still hasn't shown enough to warrant a new contract.
Id offer them Kirk straight up, or Isabella and a 4th.