From: Brooklyn, NY
Just looking into it, it seems there has been a misunderstanding. The Steam store page for Northern Inferno states:
While the campaign is fictitious, every single part of this electrifying set of scenarios has been meticulously researched to deliver an entirely new experience to please both novice players and experts.
A full stand alone game, that expands the Command: Modern Air/Naval Operations franchise, 2013's Wargame of the Year, to a new theatre: play as a single, separate game, or add it to your collection of scenarios for CMANO
15 nail-biting campaign scenarios written by Paul A. Bridge, active Royal Navy officer and Falklands veteran: scenarios are introduced by historic videos, edited and voiced over to link scenarios and set the scene for the campaign progression
6 introductory tutorials: designed and built to teach you how to get into the game in an approachable and accessible way
Air, surface and underwater combat utilizing CMANO's highly-praised simulation engine: in a world on the verge of global conflict, every unit is key to success, but only by mastering joint operations, will contenders be able to achieve victory
Conventional and nuclear operations: how far can the world go? Will they use nuclear weapons?
As ronmexico111 suggests, the 6 tutorials are those included with the base game. These are included with Northern Inferno so when people buy it as a standalone, they are given access to the tutorials to help them learn to play. I hope this helps clear up any misunderstandings, let us know if you need further information.