There were only 3 types of shotguns in Raven Shield, but 7 types of pistols (11, if you count the 4 types of machine pistols)
Considering how shotguns are important in CQB, I'd like to suggest that Rainbow Six 5 has a wider selection of shotguns, say five or six.
It's not a very important request. Just something to consider. What does everyone else think?