That behavior wouldn’t surprise me.  This summer I put out a jelly cup for the Orioles, and had Chickadees, Finches, and even a Robin all coming in for a snack.  That got me to wondering on how many other birds might utilize those resources.  In past years I’ve also seen a Song Sparrow doing the same thing.  Also, the Orioles, especially the juveniles, would attack the hummer feeder trying to get the nectar out.