I tried the team out in a couple of battles and it was actually quite good (forgot to save replays sadly ).
However, I think we can use Taunt + Defog over Will-o-wisp + Taunt/Defog on Mew. Defog is needed for hazard control, while Taunt makes it much easier to deal with opposing stall teams. Will-o-wisp is a bit redundant since it's already on Rotom-H.
As for Calm Mind vs Roar on Suicune, CM saved me against an opposing stall team (Suicune can even beat Blissey with Pressure.), but I see how Roar would be useful too.
Also, Sableye is really annoying to deal with but I think that goes for all stall teams.
However, I think we can use Taunt + Defog over Will-o-wisp + Taunt/Defog on Mew. Defog is needed for hazard control, while Taunt makes it much easier to deal with opposing stall teams. Will-o-wisp is a bit redundant since it's already on Rotom-H.
As for Calm Mind vs Roar on Suicune, CM saved me against an opposing stall team (Suicune can even beat Blissey with Pressure.), but I see how Roar would be useful too.
Also, Sableye is really annoying to deal with but I think that goes for all stall teams.