I am going to dive back into dual-boxing. I ran 4 shamans in the past, but I just want to fill the heal/tank roles for a small group of friends I have gamed with. does this offer any disadvantage to the people I see filling a 5 man group themselves? My friends are talented and will be good on taking damage. Is there any reason I shouldn't dive into this?

Also, I main a druid tank, so I will be making a DH, and then on my second account using the legion boost to start a Shaman or Paladin?

Which healer do you think better for this setup? Paladin or Shaman for going up to +10 mythic+ with my bear tank?