The key is to get Baron Rivendare and golden selfless hero :)
I'm actually getting a little tired of the Selfless Hero arms race for coming in first. For most builds, anyway.
BTW I always recommend the tier 5 Poisonous 1/1, and if possible a single Blood Gem on Baron, as anti-Zapp insurance when using Baron. Or even without Baron, if you're relying on golden Macaw to double a Selfless Hero.
If Quillboars are in and Mechs are out, George the Fallen is very powerful with a menagerie build. Competition for Gemsplitters (tier 3) will be very low, and once you get one golden and use your Hero Power on all your minions, you'll easily have a full hand of Blood Gems at the start of every turn. Get a single Thorncurse (tier 5) and your stat scaling goes from decent to galactic. It's even stronger if Beasts are out along with Mechs — you can get six minion types. The main trick to playing the build is to not be too picky with the non-Quillboar you hero power — it'll take seven turns to Hero Power everything, so start early.
You can try Divine Shield Menagerie with other heroes, too, but it's much more difficult. You need Beasts and Quillboar in — Mechs are nice for Greasebot (tier 4) but that's optional. Still Gemsplitters and Thorncurse, but you also need golden Monstrous Macaw (tier 3), golden Selfless Hero (tier 2) and not-golden Baron Rivendare (tier 5). Combine with a Divine Shield Taunt and the Macaw swing will give everyone divine shield, and you should get a full hand of Blood Gems with Gemsplitter that way. It's only a four-tribe Menagerie, but 4 out of 5 isn't bad. Positioning is Macaw first, Selfless Hero fourth. Because the build needs multiple Goldens for consistency, it's not surprising I've only pulled this off so far with Zephrys — but any hero can do it.