Why would you use a Steel-move though? Lucario is a great sweeper with Close Combat/Bullet Punch/Crunch/SD. You only really lose to Ho-Oh Support Arceus formes that are faster than you and not weak to steel (i.e. not Fairy or Rock), and Scarfers that resist Bullet Punch. Its a great cleaner after the other team has been weakened a bit, and can punch big holes with Close Combat until that happens.
+2 252 Atk Lucario Crunch vs. 252 HP / 176+ Def Lugia: 238-282 (57.21 - 67.78%) -- guaranteed 2HKO after Stealth Rock
+2 252 Atk Lucario Crunch vs. 248 HP / 8 Def Giratina: 322-380 (64.01 - 75.54%) -- guaranteed 2HKO after Stealth Rock
+2 252 Atk Adaptability Lucario Bullet Punch vs. 252 HP / 0 Def Arceus-Rock: 324-384 (72.97 - 86.48%) -- guaranteed 2HKO after Stealth Rock
+2 252 Atk Adaptability Lucario Close Combat vs. 252 HP / 252+ Def Groudon: 322-380 (79.7 - 94.05%) -- 6.25% chance to OHKO after Stealth Rock
Lugia/Giratina/WoW Arceus forms faster than Lucario that are neutral or resist BP/Lando-T/Gliscor all wall the shit out of the set you listed. Iron Tail does more damage than Crunch to Lugia, Giratina-O, Giratina-A, Lando-T, and Gliscor, Ho-Oh walls you if you don't run Rock Slide or Stone Edge (or Thunder Punch), and Aegislash walls you if you don't run Crunch or EQ (Iron Tail and Tpunch do rape Aegislash's offensive form, but without taunt, it's unlikely you will ever get the chance to fight that form.)
Bullet Punch is underwhelming. Even with Adaptability, you aren't OHKOing Arceus-Rock/Fairy. Lando-T, Gliscor, Ho-oh all wall you just for the ability to check those 2 arceus forms, which are hit really fucking hard by Close Combat and Iron Tail (Yes, they can burn or outspeed, but you're still going to be doing a shitload of damage).
Bullet Punch is also an unreliable check at best to Xerneas since it will never OHKO. It requires that the rest of your team can do 50% damage to Xerneas on the turn it uses Geomancy (read: you can't use scarf special attackers, if you use specs special attackers you can only use certain moves, etc etc)
Your calcs are also misleading: Lugia could have multiscale up and Giratina generally runs max defense in this gen unless your team is incredibly specs ogre weak.
So in conclusion: you are using bullet punch as a last ditch effort to check Xerneas, and check Arc-Rock/Arc-Fight when you could be using the manlier move, Iron Tail, which makes you perform better against the pokemon I listed above.
Also, IIRC +2 Crunch does not OHKO max HP Ho-oh after SR, so depending on what you are more worried about, Aegislash or Ho-Oh, in the last slot you can run Crunch or Stone Edge --> using Iron Tail also gives you this freedom of choice whereas otherwise you are forced to run Crunch for Giratina, Lugia, etc.