To be fair, many of us were trying to stay away from suggesting Earthquake because of how easily it busted up many of our checks. Considering that Jump Kick has literally the same amount of power and still does a lot of damage to Pokemon we want to check our CAP, I do not think it is the best idea to warrant Jump Kick. Specifically, I do not think we should make our CAP capable of breaking through Ferrothorn so easily, especially considering that Ferrothorn is a lot more durable than most Ground and Steel-types that naturally check our CAP. While we do get the trade-off of making Mega Gross and Jirachi stronger checks, cleanly OHKOing Bisharp and putting Excadrill at a high OHKO range is not something we should encourage, especially since we wanted these two mons to check our CAP (and Bisharp especially will not be able to check this CAP particularly well if it can only use Sucker Punch to beat it while at full health).
For reference, here are some calcs regarding Ferrothorn and Excadrill:
Drain Punch does not nearly as much to Ferrothorn and Excadrill, but I am not very keen on this CAP being able to cleanly OHKO Bisharp, especially since it can just heal off most damage it takes from Sucker Punch should it survive. Sacred Sword does not hit as hard as Jump Kick, but I personally still think it does too much damage to Ferrothorn and Excadrill, especially considering Excadrill has a very high chance to be OHKOd after a layer of Spikes. I heard mentions of Low Sweep, and while the modest power + utility effect does cripple a lot of our CAP's offensive checks (ie Diggersby, Scarf Terrakion, Excadrill). I honestly prefer Ground coverage, specifically because it fails to OHKO Bisharp, but Low Sweep is is not destructive enough to our CAP's bulkier checks to be ignored.
For reference, here are some calcs regarding Ferrothorn and Excadrill:
(Note: Yes, this is Rock / Poison and not Rock / Fighting)
252 Atk Mega CAP n Jump Kick vs. 0 HP / 4 Def Excadrill: 338-398 (93.6 - 110.2%) -- 62.5% chance to OHKO
252 Atk Mega CAP Jump Kick vs. 252 HP / 88+ Def Ferrothorn: 152-180 (43.1 - 51.1%) -- guaranteed 3HKO after Leftovers recovery
252 Atk Mega CAP n Jump Kick vs. 0 HP / 4 Def Excadrill: 338-398 (93.6 - 110.2%) -- 62.5% chance to OHKO
252 Atk Mega CAP Jump Kick vs. 252 HP / 88+ Def Ferrothorn: 152-180 (43.1 - 51.1%) -- guaranteed 3HKO after Leftovers recovery
Drain Punch does not nearly as much to Ferrothorn and Excadrill, but I am not very keen on this CAP being able to cleanly OHKO Bisharp, especially since it can just heal off most damage it takes from Sucker Punch should it survive. Sacred Sword does not hit as hard as Jump Kick, but I personally still think it does too much damage to Ferrothorn and Excadrill, especially considering Excadrill has a very high chance to be OHKOd after a layer of Spikes. I heard mentions of Low Sweep, and while the modest power + utility effect does cripple a lot of our CAP's offensive checks (ie Diggersby, Scarf Terrakion, Excadrill). I honestly prefer Ground coverage, specifically because it fails to OHKO Bisharp, but Low Sweep is is not destructive enough to our CAP's bulkier checks to be ignored.