not necessarily, the picture was for the medals received for action on 2/28...all in picture were recognized for action....alston wasn't there on 2/28....
Look at the "fuzzy" (photo-edited ?) object in the background of the first photograph you referenced, and colors the boat colors and arrangement.
It appears that photo (the one with Kerry in an untucked T-shirt and no rank insignia = pretty lousy appearance for AN OFFICER in the Navy with his crew!) might have been taken on a transfer boat or small craft, where it would be reasonable to have several crews mixed together.
Going on liberty perhaps, going to the support craft upriver?
The set of enlisted in the pictures in completely different.