I've completed a +12 eye, but it was not within the time limit. I think maw of souls would be my favorite dungeon with all tank team, if I can get a +15 of that with doable affixes then I will be able to complete my +15 artifact skin.

I think you may be struggling a bit now but once at 930 ilvl or so then you'll be able to go much further than an all tank team. I've seem to have hit a ceiling.