I think having randomized group comps for each dungeon would make it exciting. For each dungeon run, each team is assigned the same group comp. The chars they get all have a template gear comparable to the ilvl of what they currently run at. Along with 4 piece tier/legendary items/weapons.
They are then given 20min Prep. They would be allowed to craft 291 legendary items with unlimited resources to pick what setup they want there. Also have all covenants at 80 renown with max ilvl conduits. Then they begin the run. There would be the chance than the players decide to play the comps differently, with different legos and covenants.
This would be an interesting test of player ability. As of right now, its very boring, because both teams, practice everything down to the second. They have every route memorized, every pull has been calculated. Every comp has been tweaked and ends up being the same. And in the end, it usually results in the first group to make a small mistake loses, or the group that gets the more proc heavy perfect run.
With randomized comps, we would get to see the players adapt on the fly, and try to push the key, all the while adapting to a different comp.
Just think of two teams going head to head playing Brewmaster, Resto Druid, Ret Paladin, Shadow Priest and Ele Shaman, for one round. Then the next dungeon they are playing Prot Warrior, Disc Priest, Destro Lock, Feral Druid, Fire Mage. Just getting thrown a little bit of a hodge podge setup, and having to think how to clear and push with that. For me at least, I would watch that, just to see what was next and how they would adapt.
I think that kind of format leans to be a little more exciting for viewership than watching the same meta group setup every dungeon, do the exact same pulls they have been doing all tournament, in the same order.
Its my opinion that the MDI isnt fun to watch, because the groups are so rehearsed and practiced on the meta comp and the dungeons with that comp, that there are few if any surprises.