Some takes I have on minor moves and EV choices:
Mudsdale: Before april 1st I would have said that spdef mudsdale is the superior build by far. After toxtricity and rotom heat left, I think physdef and spdef are roughly equally viable, but I think we need to see more spdef mudsdales. I also believe that adamant spdef mudsdale has a place. Adamant mudsdale with 0 attack EVs can get a guaranteed ohko on kilowattrel with stone edge, 28 evs get you the guaranteed 2hko on max defense oricorio, going up to 80 or so gives you a chance to ohko physdef coalossal and every point helps make stuff like Sylveon or Slowbro less able to exploit mudsdale. A ground type that gets easily worn down by Kilowattrel is just unreliable, and there are still some special attackers than mudsdale can reliably beat 1v1. The real thing I want to talk about with mudsdale is moves. Simply put: stop running heavy slam. You lose to rotom, you lose to kilowattrel, you lose to oricorio and you just don't do enough damage in general. The better moves are body press and stone edge. body press gets boosted by stamina to the point where even resisted body presses do decent of damage to flying types. Stone edge is the much preferred move on spdef mudsdale though, since it has a good chance to ohko kilowattrel and does good damage to other flying types like oricorio and altaria.
Kilowattrel: Speaking of this bird, I think roost is a bit overrated and not required on all kilowattrel sets. If you are relying on kilo to check flamigo then roost is needed, but otherwise I think that tera blast helps you have more impact overall. Before the april shifts and ban I was fond of tera rock because it let you beat hattom and other kilowattrels, but I'm not sure what the best tera blast type is right now. Water seems like the good generic tera type, rock still beats other kilos and flying types, ice is good for bolt beam coverage and now you don't need to worry about heattom walling you.
psyshock: It seems like even after toxtricity and heattom left, Blissey is still going to be a fact of life. For that reason, I think psyshock should be the standard psychic attack on these two. It doesn't do >50% to Blissey with scarf, but the damage is still good and it allows you to run Blissey out of soft boileds faster even if you trick your scarf onto something else. Specs sets on these two really want psyshock, since it allows them to break the blob without having to trick their item.
Mudsdale: Before april 1st I would have said that spdef mudsdale is the superior build by far. After toxtricity and rotom heat left, I think physdef and spdef are roughly equally viable, but I think we need to see more spdef mudsdales. I also believe that adamant spdef mudsdale has a place. Adamant mudsdale with 0 attack EVs can get a guaranteed ohko on kilowattrel with stone edge, 28 evs get you the guaranteed 2hko on max defense oricorio, going up to 80 or so gives you a chance to ohko physdef coalossal and every point helps make stuff like Sylveon or Slowbro less able to exploit mudsdale. A ground type that gets easily worn down by Kilowattrel is just unreliable, and there are still some special attackers than mudsdale can reliably beat 1v1. The real thing I want to talk about with mudsdale is moves. Simply put: stop running heavy slam. You lose to rotom, you lose to kilowattrel, you lose to oricorio and you just don't do enough damage in general. The better moves are body press and stone edge. body press gets boosted by stamina to the point where even resisted body presses do decent of damage to flying types. Stone edge is the much preferred move on spdef mudsdale though, since it has a good chance to ohko kilowattrel and does good damage to other flying types like oricorio and altaria.
Kilowattrel: Speaking of this bird, I think roost is a bit overrated and not required on all kilowattrel sets. If you are relying on kilo to check flamigo then roost is needed, but otherwise I think that tera blast helps you have more impact overall. Before the april shifts and ban I was fond of tera rock because it let you beat hattom and other kilowattrels, but I'm not sure what the best tera blast type is right now. Water seems like the good generic tera type, rock still beats other kilos and flying types, ice is good for bolt beam coverage and now you don't need to worry about heattom walling you.
psyshock: It seems like even after toxtricity and heattom left, Blissey is still going to be a fact of life. For that reason, I think psyshock should be the standard psychic attack on these two. It doesn't do >50% to Blissey with scarf, but the damage is still good and it allows you to run Blissey out of soft boileds faster even if you trick your scarf onto something else. Specs sets on these two really want psyshock, since it allows them to break the blob without having to trick their item.