Bag of the Mammoth Rider

The Starter Pack from Steam comes with two bags, a large one and a bit smaller one called the Bag of the Mammoth Rider. Does this bag have a special function?

Is there some way to use this like saddle bags for extra space while on your mammoth?

Is it another great idea that Funcom didn't implement? [my guess}

Or is it some sort of reverse intelligence test for the mathematically challenged? Should I use the 16 spot bag or the 20?
I have to take off my shoes todecide which is bigger.

no you can only have one bag. Not sure about the starter pack you mention, just use the biggest one.

Regarding the Mammoth bag, I think is from the launch offer which came with bag and War Mammoth mount. The other one (bigger) you have probably is part of the steam pack instead