Tbh none of this matters unless you:
- Are missing out on damage balls because of your lineup in group raids
- Are attempting to solo Flareon or Alakazam, duo Tyranitar or Moltres, or trio Zapdos
I personally set my minimum standard to power up at 10 if the other two stats are spectacular (15 14 or 15 15)...but I can also completely disregard the other two stats if the attack is 15 (e.g. I've powered a 15/2/1 dragonite before)