I know that the ortlieb rack-pack 24 liters and rack-pack 31 liters can be combined with Back-Rollers classic but does anybody ever tried the 49 liters version with back-rollers pro classic (70 liters)?

I know...I pack too much stuff, but I like my luxury items on camping!

Actually, I ride with a full loaded trailer with 100 liters capacity and two back-roller classic panniers (40 liters) and I want to switch to 70 liters panniers. So 70 liters panniers + 31 liters rack-pack will have the same capacity of my trailer, but no more space for food or miscellenous items. That is why I want to know if I can attach the 49 liters rack-pack with back-roller classic pro (70 liters) on my rear rack. I will put my two back-roller classic (40 liters) on my new front rack.