As a former wow player, i’ve seen this.
It’s a horrible solution.
If you want to play something with a tank and healer… unranked… easy enough.
Just poiting out the obvious … QUICK match… not balanced match… not cry cause it’s unfair match
Quick Match
20 mins not quick enough for you ?
People wanted balanced teams. Sure, but queue times will go up. Peope want faster games. Sure, but teams will be unbalanced then.
Either accept it, or play something else besides assassins.
Another solution is to give quickmatch an option to what you want. Select Balanced teams for a balanced team matchup, which results in a longer queue time. Or select random, which will give you a random team. No balance, but faster queue time.
The problem is this already exists. You have QM and UD. QM was supposed to be fast and unbalanced and UD was supposed to be slower with a draft which should give players and option to build balanced and optimal teams.
The problem is Blizzard failed to promote this. They completely failed in educating players about mode meanings and mechanics. Instead they are building second “UD” without draft to silence small, but loudest part of the community. I don’t think this was a good approach. At least they should change the name of the mode, because it’s not quick anymore 
I think better way would be revert QM back to alpha state and start working on UD including developing algorithms to detect and punish people who consistently prove to be trolling or picking against their own team there in order to improve image of UD mode and popularize it for all those people who want to have “balanced teams”.
Other option for improving UD without punishments would be to implement mechanics which would teach people on how to pick and motivate them to try and learn important, but unpopular roles (e.g. play the support well and get a free chest).
The thing is, people always cry about QM not being balanced enough, so they are trying to balance QM matchmaking. Then people will cry about QM queuing for too long so what do you want???You cant have all in one
Clearly said by someone who doesn’t play UD. First pick Abby, two lane map, GG game.
Because that never happens in HL/TL. And you definitely never get it in QM… Sure. Clearly said by someone who doesn’t play this game.
Play Unranked.
It’s much more quick. From what I saw, people also build some form of a composition there, too.