Hey, thanks for the report and the video. I tested this myself today and confirmed it's working as intended. When General Grievous gains 1 stack of Translation from C-3PO, his Max Health is increased by 30% and so is his damage output.
Please bear in mind that General Grievous' basic attack inflicts increased damage if the enemy target is debuffed. Also, Critical/Normal Hits don't always deal the exact same amount of damage against the same target under the same conditions.
Even looking at your video, General Grievous (without Translation) deals 61.190 Crit Damage on Clone Wars Chewbacca (while debuffed). General Grievous (with Translation) deals 69.471 Crit Damage on Clone Wars Chewbacca (while debuffed). Looks like Translation on General Grievous does make a difference in his damage against the same debuffed enemy target.
Was this what you were referring to or something else?
Thanks!