Water main has a big flaw with the fact that her barrier user is not Konoha ninja, so Iruka doesn't shield them, and doesn't give as much benefit to the team overall. I would either go with your team, or Asuma WB, Iruka, Haku, Water, with Haku having to rely on his own passive boost.

Reserve seal is good too, but you have a point here. I am no water main expert, so I will leave this for some more experienced person to consider :D