Good post, and a fun read

Your friend had a few things going for him, his much trumpeted superior intelligence,
and more importantly, a knowledge of basic tactics, like flanking, as valid today as a 1000 years ago.
He also picked the right faction for a n00b, the Danes being in a safe starting position, with access to sweden, the holy grail of economic development. His initial strategy was also by the book.

However this only confirms what we know, it simply isn't challenging in a traditional way, so we need to add houserules and play in a certain way to have fun. And fun being the operative word, I still get tons of it from M2