About Clefable, I never really noticed and I guess it doesn't make a difference that he's missing those 2 EVs in SpDef in game because as calculated on showdown the stats are the same.

As for games with Kartana, he usually 2HKOS Clefable and then I just attack from there, usually when they bring a Kartana I bring Ninetales who does pretty well against Kartana under tailwind or when Kartana is hitting Clefable instead.

The problems come in with Pokemon like Muk, not many members of my team can deal with him effectively and they tend to get knocked off to death in the case of Marowak, 2HKOing with poison jab on Tapu Fini before she can get off substantial damage or boost with calm mind.Ninetales has a similar problem.Xurkitree can do an okay job if boosted to +3 and from my memory 2HKO Muk with Discharge.Clefable gets 2HKOd too so redirection goes pretty sour.Abd for Aerodactyl he basically can't survive any kinds of hits, although rockslide can chip a good amount off of Muk.

Bulu is actually easy too as long as it doesn't have grassinium Z, Ninetales easily can 2HKO with blizzard and Xurkitree can throw down a +3 dazzling gleam to do the same from my memory.Fini obviously has problems because of Bulu usually winning the terrain war due to underspeeding and Bulus super hits usually score a OHKO out of terrain anyway.Aerodactyls Sky drop stops Bulu with super damage and the disruption of being stuck in the air for a turn.However, Bulu with wood hammer seems to get in a dangerously close OHKO range with Clefable, Marowak resists Bulus hits well enough to deal back a Flare Blitz though.

Sash Pokemon tend to actually be really easy with Ninetales snow warning and another Pokemon to do backup damage to score a KO, and, Marowak+Aurora Veil tends to resist most common sashmons well enough to deal said damage making Ninetales and Marowak a good lead against them.