Confusion Mewtwo not viable for Alolam Marowak Duo?

Psycho Cut's higher energy gain, in theory should allow for more Shadow Ball output, so there's that. It's also way more dodge friendly should you be up against an Alolan Marowak that's also running Shadow Ball.

More like prove us you can duo marowak with confusion/shadow ball mewtwos.

In cases where the charge move has better type advantage than the fast moves, PC gives Mewtwo higher cycle DPS than C does. It's a relatively small difference on average, but it's there.

No reason not to have the optimal moveset against hard challenges like A-Marowak duo.

According to pokebattler.com, confusion and psycho cut are tied neck and neck for time to win.
Psycho cut is only important against psychic types where they resist confusions damage so youd rather have the extra eps from psycho cut.