Water slide decals, am I overdoing the cut out?

No pics because I don't think they are needed. I'm working on the Moebius Wonder Woman and putting the stars on her trunks. I did a few last night, using Micro Set, micro sol. They look great. Part of my process was also using an exacto knife to cut close to each individual star shape rather than just cutting them individually as squares. Is that overkill? What dissolves in the water, is it the top layer that holds the decals on the sheet? Do I need to cut as specific as I have been or does that top film just dissolve in the water. Thanks