ok....
i think excadrill really provides nothing for this team, and the bulky version is really only useful as semi-stall, whereas the offensive one is only useful on sand teams. i think your best bet is to replace it with a latios, to use for hazard control, as well as a landorus check, since that can potentially sweep your team at +1. i would consider sleep powder on venu because you dont have a lot of switchins to metagross, and venusaur usually lures it in. i would also run up 44 speed on rotom-w so you can outrun bd azumarill. i would put sludge wave on landorus over focus blast, i still dont think skarm is common enough to warrant running it, plus you can chip the poke anyways. you could also run rock polish on there to sweep offense teams. that's about it, maybe a hippowdon over heatran with sandforce so you arent as weak to lopunny, metagross, sd bisharp
paired to kaori & vrai