Go ahead. Give me the worst teamcomps you got. We will try to debate for their viability
Wrecking Ball, Roadhog, Lucio, Zen, Mei, Bastion.
On 2cp attack I can not imagine a better comp to confuse the enemy.
Hog body blocks and hooks, Ball pops up skeet for Bastion and Zen discords, Lucio speeds Mei around and freezes.
Hog and ball torture, sym, bastion, zen and lucio. Good luck 
Sym bastion teleporting around while the ball and Lucio boop targets into his view and hog body blocks and zen discord’s the target
That’s so unreal it would never happen 
ball goes in and dies, hog is an ult battery who can’t even peak for more than 2 seconds without dying and bastion is dying every time he enters turret mode while Lucio is redditing on the walls. There, I fixed it!
D.va, Hog, Widow, Pharah, Lucio, Brig.
This happens in real games no kidding.
Doomfist, Torb, Sym, Bastion, Widow, and Pharah.
Frankly, this can work, but like most unorthodox comps, requires sufficient coordination.
This comp has unreal burst damage. Hog, Phara and Widow can all get a pick within a second.
Lets imagine Anubis point A. This weird comp is attacking against your commonly-found Rein, Zarya, Ana, Moira, McCree, Genji.
Instead of everyone charging left or right at the first choke, Lucio speeds Brig and Hog right and immediately up and then down on to the empty point. Dva and Widow go up on the platform above the choke 1 second after the speed boost. Pharah can go too, or attack at a slightly different angle. Assuming the defending team isn’t as coordinated, they’ll be split on which team of 3 to pay attention to.
This is when individual skill takes precedent and someone has to get a fast pick. Widow snipes one, Hog hook combos one, whatever. Once a pick is made, Dva and Pharah fly to the point and just bombard with missiles, while Widow is completely free to take shots from afar.
You may argue and say just get the McCree and Genji after the Widow. I argue that an unchecked Hog freely flanking with 2 supports is much worse. Not to mention they’re backcapping the point so most teams will instinctively just all retreat to point.
I’m just rambling but I hope my point gets across as to how this COULD work out.
I get you. So basically…
I guess if you get a dink and a hook you do win the fight. Just needa pray your face doesn’t get blasted beforehand 
While a very strange comp, it can work for 2cp maps, especially first points. Or certain KoTH maps.
What should happen is the Sym tps everyone onto Point A directly (imagine Hanamura). Like the other comp I argued for in my other comment, pick potential is huge here for this comp. Coordination is necessary of course.
Once tp-ed, Ball can choose to start swinging on the bell or go for a distracting flank, while ready to fall back to point quickly. Lucio speed boosts as everyone comes out of the tp. Bastion and Zen, with the speed, can settle in a corner and coordinate discorded targets. Hog and Torb will act as the main front line, with the turret somewhere shooting from a different angle as the Bastion. Sym will throw all 3 turrets along the walls.
Then, player skill takes precedent. With so much pure raw damage, someone must take advantage and get a kill. With this comp, any kill will snowball as it will require the entire opposition team to work together to even survive a fight on point. Whilst the brawl is on point, Ball could piledriver the squishies who stay slightly out of the point, either bursting them down himself or causing enough confusion for his team to capitalise.
Its very situation specific, but it can work.
Yeah, pretty much. I don’t mean you need a super high skilled player to make it work though, I mean something along the lines of, if you work to the strengths of your team and anticipate the reactions of the opponents, most weird comps CAN work somewhat.