The higher the discharger rate, the lower the voltage.
Even though 1,15 looks like close to 1,40, it's quite a big difference. Multiply by 6 (cells), means 0,25*6=1,5 volt more for the motor (average). Thats similar to using 7 cells packs, instead of 6..... Huge difference.
However, matchers are using different equipment and methods, therefor comparing numbers from two different companies aint nessecarily the true picture.
Schumacher Mi5 - Sanwa MT-4 / RX-462 / KO Propo PDS-2123 - Nosram 5600 X-treme Saddle Pack - LRP SPX Zero/X12 17,5 - Nosram Stealth Touch Evolution - MAAS SPS 9250