Check out some of RedSorc's videos in the dungeon section. He is having good luck with a Blood DK, Restro Druid, Hunter x 3.

I gave up on the 5 pali tank and switched to tank/helaer/3xret, then I gave up on that and decided not to push for high mythics this season. Which makes me sad because I did the m+15 achievement in Legion with 5 pali tanks and I really wanted them to work this time too. Maybe when I get some better gear.

I do have 5 BM hunters with about 380 iLevel. I have not run any mythics with them yet, and now I am curious how they would do and I might try that.

I will stick around to hear what others say about this. I may have given up too soon, maybe I just need to put more effort into pushing the higher mythics.