This is just a really tiny nitpick, but the Defiant set notes that the Atk EVs are added to OHKO Latios after rocks, but not that much investment is necessary:
64 Atk Life Orb Thundurus Knock Off (97.5 BP) vs. 4 HP / 0 Def Latios: 263-309 (87.6 - 103%) -- guaranteed OHKO after Stealth Rock
68 Atk Life Orb Thundurus Knock Off (97.5 BP) vs. 0 HP / 4 Def Latios: 263-309 (87.9 - 103.3%) -- guaranteed OHKO after Stealth Rock
64 Atk OHKOs 4/0 Latios and 68 Atk also OHKOs 0/4 Latios.
Unless, of course, it's just an arbitrarily larger number than 68 to OHKO random 8 HP or 8 Def Latios. That's not a bad idea actually.
64 Atk Life Orb Thundurus Knock Off (97.5 BP) vs. 4 HP / 0 Def Latios: 263-309 (87.6 - 103%) -- guaranteed OHKO after Stealth Rock
68 Atk Life Orb Thundurus Knock Off (97.5 BP) vs. 0 HP / 4 Def Latios: 263-309 (87.9 - 103.3%) -- guaranteed OHKO after Stealth Rock
64 Atk OHKOs 4/0 Latios and 68 Atk also OHKOs 0/4 Latios.
Unless, of course, it's just an arbitrarily larger number than 68 to OHKO random 8 HP or 8 Def Latios. That's not a bad idea actually.