If you had any doubts about secret Hunter being a legit deck this should 
change your mind. This is the Superjj Top 50 Legend Barnes Secret Hunter Deck. I watched him take this deck into the top 50 at legend and he was tearing up all classes.
The only minions you really don’t want from Barnes are Secretkeeper, Fiery Bat, and Houndmaster. So you can wait until you’ve played most of these, or roll your luck as there are 4 minions that aren’t too bad. It’s clever deck building because it puts the % chance of a good minion on your side.
There is a lot of decision making but it’s a strong deck in the current META and can take you to high legend for sure.
General Mulligan Strategy for Barnes Secret Hunter
Don’t hold on to any secret, you’ll jam your hand up. Mulligan for Secretkeeper, Fiery Bat, Kindly Grandmother, and King’s Elekk.