Is it a mistake? Ann Thread translation=100 Stakes, WhitePaper (words≈6000)=1 stake?
when i was reading this exactly i thought same

, white paper writing is not easy task , need mind blowing words , they should revise this , white paper translation should have 500 stakes .. then i can think for Arabic
The stakes are proportional to the specific campaign. In the case of the ANN Thread, there are additional actions that can be rewarded stakes, therefore the actual translation is weighted more. For the Whitepaper translation campaign there aren't any other additional actions so the actual number of stakes doesn't necessarily matter, each translation gets the same proportion of tokens allocated for the campaign.
Thanks for the clarification.