EV Training

You know how Rowlet is the starter Pokémon you're supposed to choose because Ash catches one in the series, and standard EV-training would be to EV-train him in Speed and Sp Def. and Inkay is right above the Professor's Lab.

FYI, My Rowlet is Sassy natured and I'm training him Sp Def. and Speed.

I personally prefer Attack and Speed on Decidueye - that guy hits like an absolute truck with some very unique coverage from his typing. Not sure I'd see much use in Sp. Def. on him though, what's got you choosing to do that? :o