There are both pros & cons when you move Itachi to move 1, not just cons.

Pros:

1. You can 5 stars him easily and make him a powerhouse with bond mystery, plus his bond mystery actually hit really hard.

2. Itachi on hit effect is tag so it won't be a pain in the a$$ when fight against mirror reflect like Shisui.

3. You still be able to use Shisui pretty much right after Itachi to guarantee a 2 rounds chaos on the enemy target of your choice.

Cons:

1. Itachi don't have dodge, so masked man can easily counter you.

2. You waste his cleanse passive.

3. His bond mystery for some reasons (I don't know if this is bug or not) can't be reset by Killing Intent or Red Lotus Secret. So his mystery CD still gonna be 3 rounds after round 2.