The higher scorestreaks in Black Ops 3 are apparently not yielding good enough results for Treyarch according to Vonderhaar. Subsequently, these will be buffed (stats improved) in a future game update.
Multiple are under-performing from target design goals and will get buffed in future update. Work in progress. https://t.co/m4NPgfVu2U
— David Vonderhaar (@DavidVonderhaar) December 2, 2015