>>54720126This is where you evaluate its helping speed and carry limit.
Base stats before natures and subskills, Vaporeon is unfortunately less effective than Squirtle. This is ignoring the main skill though, which Vaporeon will be able to trigger more often as a skill specialist.
The berry finding S Vaporeon can outperform a neutral Wartortle, and potentially beat a Blastoise with enough main skill procs, but only gets +1 to its main skill rather than +2.
The pool of ingredients and berries they can gather happen to be identical, but Vaporeon gathers fewer ingredients overall making it reliant on that main skill.
Bottom line really is you want a Blastoise, not a Vaporeon.
Of course, you can always play with your favourites, but the reality of doing so is that the game will take longer to progress.