So Dooku does Scatter on troops and and coheres those troops into melee with Grievious.

Is Cohesion Into Melee possible? I thought I saw somewhere where it’s not, but can’t find it.

from page 21 of the rules reference:

When placing a mini in cohesion, it cannot be placed in base contact with enemy minis, unless the unit is in a melee (see "Melee" on page 48).

so no I don't believe you can do what you are suggesting

@Mace Windu is right, melee can only be started by a unit leader entering base contact with an opposing mini, and Scatter doesn't move the unit leader

You might not be able to Scatter them into melee, but you can potentially (depends on exact distances) Scatter a unit which was at Range 2 into Range 1 to use Force Choke and/or Force Push. The former is a neat way to take out heavy models.

Thanks guys.