The only realistic setup you mentioned that could pull off some heroics is the 1 Paladin 4 shaman combo, and even then it would be difficult, but at least you have a solid tank and 2 healers + 2 dps.

Overall with those specs they wouldn't be effective in PvP at all - though a simple respec would do the trick if you already had that in mind.

Heroics aren't meant to be easy, which is why they removed them from being a requirement for guild progression into the top tier zones. In my opinion the overall time spent vs reward isn't worth it as well. I would build a team that can do normal runs successfully and get my gear through quests/ PvP rewards. Arenas give insane amount of top tier gear for low input.