Thanks for the trade - and I do apologize for the wait time.
Solid counters to Dragons/Dos can be from all three though :P Basically any water can be used as a counter to those, lol. Anyways, CroCune is imo superior for longer lasting bouts (toxic can really run down Milotic). Offensively, imo, Timid Suicune does the job better too. Though that's true, I am biased since Suicune is my favorite pokemon, haha. Vaporeon really plays a completely different role though, so I guess it'd be hard to do a comparison there, lol.