The usefulness of logistics for the main hero.

This is, of course, for those who don't mind managing ten heroes in the campaign.

I think this is the key point. In general, you can win in single-player mode with almost any set of skills. There are one or two skills that specifically make life easier in a given mission or campaign, and you can put almost anything else in the remaining slots, so single-player mode isn't a very good indicator.