I currently run your group3 setup.

I have a druid tank, resto shaman healer, 2 elemental shaman dps, and a mage. Nice buffs and portable. I have one cc which is very nice to have. Right now the only thing holding me back is gear. The resto shaman has about 1150 healing now and the dps all have 600 damage or less. Once I get their gear improved I will have an easier time. My druid is wearing T5 so he outgears everyone. What has wiped me more than anything is when a Mind Control mob takes over my tank and all the mobs rush my team while my druid owns the squisy guys.

I also have a pally tank that can swap in. His gear is not as good. If he had equal gear to my druid I would make him tank more often. The problem with the druid is when you have a large pack of mobs and need to keep aggro. Swipe works ok but you really have to watch out with your cc. The last patch said swipe, chain lightning would not break cc but that is a bunch of bullshit. If that was fixed I would have a much easier time with my group.

Sometimes I wish I had a 5 shaman group to burn through stuff. Tanking + Healing is pretty hard. It would be much easier if I could just nuke with everything instead of watching health bars and dpsing mobs. It takes more effort to have a tank healer group than it does with a nuke them down. Also, pvp with 5 of the same dps is much better than my group in pvp.

I would recommend you do a 5 shaman group then make a tank or mage with other toons later.