Just piloted this little list to masters. After the nerf to instigator I was looking at other 3/3s for 2 and Bartholo seemed pretty seducing. His base stats are pretty nice, and in the right circumstances he is devastating. Also, activating him or Fenris and simultaneosly dropping a stormhalt knife for free feels pretty good.
Minimum 3 power sources on the go, including golem and varas favor, 2 on the draw. Otherwise you're looking to have some 2 drop units and removal.
Blackhall warleader is almost always the first unit to run out. If you have bartholo and ponysnatcher in hand, lead with ponysnatcher to immediately buff bartholo next turn when he hits. If the opponent is likely to have turn to seed, open contract or milos, try to run out your golems ASAP. When your Golems are turned off in grindy matchups Tasbu is your best target to shuffle into your deck with wasteland broker. Betray the cause is nice when the opponent has a few big units that outclass yours and keep you from getting the last points of damage in. Apart from all that, just look to curve out nicely. Against control decks its often correct to drop fenris and immediately activating instead of dropping multiple units. Bartholos ability is used best when the opponent is already low on cards, but I used it pretty aggressively when it was risky dropping more units. Last of all, get a Doctor's degree in combat math. Getting that wrong is pretty bad since you often run low on life, I've had multiple games where I won at below 5 life. Hope you have fun!