I box two druids (currently lvl 34) and a normal Feral Charge has never broken my follow. The times that it has broken:
1: Charging up a very step hill that you normally can not walk up (WSG Horde GY)
2: Jumping and charging mid flight over an object.

But what do you expect will happen using charge then. For PvE content, I use charge and while my 1st druid charges in, I make the other druid stand still. The gap that is left in between them is enough to keep the other healing out if the increase aggro range area. (After standing "X" yards away, you create "Y" amount on less aggro.)

For pvp on the side, i'm assuming your meaning BGs. Because if your on a PvP server, you will be doing pvp even when you don't want to. Got to love lvl 70 toons camping the quest turn in guys.

Some of the classes you listed would be ok in pvp, but not the best, but still do ok.

2 Hunters can do ok just make them both BM spec'd. Though you can't run in just by your self, your best bet is to stay with the group, and attack from range while your pets go crazy (and grow big and red). Also guarding stuff is good for this setup. Flare / Trap will help, and if you get a rogue on you, with BW they should die pretty fast. (I use to love rogues trying to stun lock me on my old main when he was BM)

Warrior / Priest is ok as well. For this setup i would guard a node. Hide the priest, and have your warrior out in the open for all to see and attack. Most will come in attacking the warrior, don't do anything with the priest at first until your warrior needs a heal. You will probably get about 3 heals off before they notice your priest. If they run to the priest, either shield up or fear them away. For this you also need to know the range of your healer. While none are around, run around to find all the LoS areas and furthest range you can be to get a heal.

I have used the priest warrior strat a few times on my druid. It's little easier because I can shadowmeld the healer one while the other runs around and fights. For a PvE / PvP combo, I love the 2 druids I got.
I can:
Tank / Heal
Rogue like DPS x 2
Mage like DPS x 2
2 Stealths for getting pass stuff (very nice when a lvl 70 toon is killing everybody in the city, yet you can still walk around and do turn-ins)

Hope this helps and gives you a little idea what can be done with Hunterx2 and Warrior/Priest.

Ziie