>>21889459252/128/128 is bad unless you're using some stupid gimmick like Shuckle. If you're speaking competitively you want to EV for whatever your potential threats are.
For example, a defensive Torkoal might run 252 HP / 252 SDef / 4 Def. However if you are running into a lot of Hippowdon you might run 252 HP / 160 Def / 96 SDef so that you can survive 2 Earthquakes + Sandstorm damage with Leftovers recovery and still leaving you with SOME special bulk. However, you could have survived one Scald from Seismitoad before, whereas now it will OHKO you. It all depends on what you want to survive.
Competitively though please don't use mixed attacking Torkoal it's built as a defensive pokemon and can't do anything else.
If you're just playing in game, with friends, etc. none of this matters and you should do whatever the hell you want.
