Good post. Good information that should help a lot of players.
AJ - Excellent guide and impressive 17k jump!
Not sure that I agree about increasing skill level of dupes. It isn't cheap. Almost all of my heroes were 1/9 until after I hit 130k might. Now, most are still 2/9, and the decision to go to 3/9 is difficult: for 50 heroes, it will cost 25k shards. Meanwhile, the same amount would allow me to bump a 7/9 hero to 8/9.