Yes it is
That's why I make sure everything is equally balanced and measured properly. OEM specs have to much variances and tolerances for me.
That little bit of weight difference,along with clutch balancing +/- 3 grams can cause vibrations,poor clutching,poor belt life, heat, hard on pto bearing, etc..... The list goes on.
The best money you can ever spend is getting your clutches perfectly balanced. This adds to the efficiency of the system and will give you better performance all around.
This always gets overlooked. It shouldn't.