Is it right to implement and appraisel the employee with this system

Dear All,
I have a difficulty decesion to make that I have 3 of wonderful employee which helping me, there all malaysian and malay races while this is a chinese company which very famous around the hole malaysia.
Now, this is the letter I received, what should I do? Is it right? Where should this goes to?
This is the email which send by the person in charge:

Dear XXXXXX,
After check thru Prod. Clerk year end appraisal found all 3 clerk you put under high performance(80% & above), as I mentioned(even DRM meeting mentioned) due to this year company implemented Bell Curve system even 3 staffs you need to put as below:- High performance (80% above) = 1 person.
Average performance (60%-79%) = 1 person.
Low performance (59% & below) = 1 person.

Please re-do their appraisal follow above bell curve system and this is a must.

I on MC today and tomorrow I will pass back the appraisal to you for re-do.

Please take note. Thanks.

Regards
XXX XXXXX