Why were saddle bags so small?

Why were the standard issue '59 saddle bags so small? This episode checks out the relatively small saddle bags and what the military wanted in them; and what they didn't. What do you think, were they on the right track, or would larger ones made troops more effective?
Check out our sources:
Congdon's Cavalry Compendium:
www.11thovc.co...
Civil War Digital Digest:
civilwardigital...
11th OVC Research Library:
www.11thovc.co...