Difficulty (4) - Unless one of your opps is wearing no resil, pretty much the only way you'll ever win is by outlasting them until Shaman is OOM. Your best bet is probably staying on the Shaman, switching to the Hunter whenever ES drops off. Make sure you kill the regen totems as well as groundings (hand of reckoning is cool); you should also be able to gib the Hunter's pet with relative ease. To ensure your Druid can innervate safely, you need to first get rid of Shaman's trinket - either some CC on him while going hard on the Hunter, or a HoJ on top of a judge crit should do the trick. Afterwards, wait for your HoJ + Repentance to be off CD, then have your Druid innervate, you probably won't kill the Shaman like that since Hunters are annoying, but it gets you a good 12 seconds free from purges. As long as you keep up decent damage and switch targets smartly, the Shaman will have to either stop using his hots / ES actively, making them more susceptible to gibs, or oom.

If you need the innervate badly and can't setup proper CC on the Shaman, your best bet is putting as many trash buffs on your Druid as possible - sacred shield, hand of salvation / freedom / sacrifice, even throwing some heals to get sheath of light might be worth it. Also, considering the Shaman will likely have to go nuts aggressive to get that Innervate off, popping Avenging Wrath and going for a kill on either of them could work.

Alternatively, chaining cyclones on the Hunter while Paladin stuns and tries to kill the Shaman, followed up with a repentance / bear bash could maybe get you a kill, just have your trinket & BoF ready for the Hunter's peels.