There’s a tanking archetype known as the “Stone Wall” that’s present in some games (though how effective/fun those characters are varies).
I think you’ll find it’s in Overwatch too, but it’s called Ice Wall here 
Put Zen in DPS role too.
I figure if you have an offtank AND a barrier tank.
Then you have the Barriertank cover the medium/long range threats, and the Offtank act as a short range bodyguard and peeler with utility.
Kinda like how MainHealer and OffHealer are balanced.
Where it’s usually most desirable to have one of each, for full coverage.
The biggest flaw in Overwatch’s balance design is an assumption that every team will have a barrier.
If they want to assume that, then they need to give every Tank a barrier. If they don’t want to assume that, then they need to adjust both barrier health and damage accordingly so that double-barrier compositions aren’t overly oppressive and so that barrier-less compositions are not instantly decimated by burst damage. Anything else leads to the stale Tank metas that we have now.
Keep in mind that Blizzard themselves make no distinction between ‘main’ and ‘off’ tank - the only categorisation they’ve ever mentioned has been ‘anchor’ tanks like Reinhardt and Orisa. The same applies to Support.
Well, here’s a scenario to run through with the changes I listed.
✅ Fixing BarrierTanks and OffTanks
- Orisa/Sigma, each with 350hp, and weaker Fortify/Grasp. (With no Mei either)
- Hog/D.va, each with 600hp, and kinda 900hp on Hog.
- Hog/D.va use speedboost+Matrix to get into close range.
Which team has the upperhand in the upcoming close range brawl?
The way I see it, not having an offtank, means that you get run over by Speedboost/Dive comps.
Much in the same way that not having an offhealer, with a big defensive ult, is a big liability for getting run over.
Also DoubleOffTank would have it’s own advantages, with raw HP advantages over Barrier compositions.
Also incidentally, by lowering the HP on those tanks, it would be putting them into instakill range for PulseBombs. Which would drastically benefit Dive compositions.
This is absolutely the way it should work. In practice it doesn’t due to excessive CC and powercrept burst damage being able to stop almost any dive dead in its’ tracks.
In practice it doesn’t because Orisa goes CC immune with the equivalent of 800hp, as well as a team wide Displace/Slow.
Sigma throws out a Matrix that heals him, then throws out an unmatrixable flashbang,
And to top it off, Mei fulfills the function of an offtank, with Slows and Walls.
And by the time you cut through those selfpeels, it’s already been 3-6 seconds, all the Dive momentum is lost, and Lucio boops then just speedboosts them to safety.
It’s hard to balance tanks.
Make them too defensive, and people will find them unfun. Make them too offensive, and all of a sudden, they’re like DPS, but better.
Yes, it would be fun if tanks were like raid bosses, who no one could reliably 1v1, and required multiple players to take down. But that would just lead to things like Triple Tank, where there’s be tons of tanks on a single team.
It’s actually not as hard as you’re making it sound when the game is played in a 2-2-2 format where there has to be 2 of every role on every team. Triple tank meta is not a concern when there can only be 2 tanks.
Problem is the only way to accomplish this is either… give the tank damage to fight back… in which case they’re immediately nerfed because they can do enough damage to fight back. Or give them enough sustain and tank abilities to live through the dps… in which case they’re immediately nerfed because they can live through a dps attacking them.
In short, the dps community which is the majority of the player base just wants free ult charge
Who’s losing 1v1’s as a Tank vs a Dps??? 
People don’t associate a Tank with people being able to do damage, just being a bullet sponge/shield bot.
I prefer the idea of being a slow, extremely dangerous thing that is very limited in its ability to deal extreme damage that warps the battle field around it. In OW at least they’re extremely reliant on other units to support its glaring weaknesses of range and size (increased damage taken). The Damage class ensures they’re not run over or easily outmanoeuvred and Supports ensure they aren’t ground down.
Theres a reason you don’t make an army full of a single unit 
No.
That’s just making tanks blatantly over powered to try to fix a larger problem.
That’s not balance at all.
Just like in everything else in OW… the problem is that DAMAGE. IS. TOO. DAMN. HIGH!!!
Reduce damage overall, and tanks will be able to do more than just be shield sponges or target dummies waiting for heals.
Absolutely disgusting way to design a game.
Popularity is not solely based around damage. It is also based around the appearance and how a kit works. Which is basically balancing around the subjective term of “fun”.
No, Overwatch always has been and should always be about unique characters with unique ways to impact the game. Making tanks more damaging and less tanky is the wrong way to go about balancing Overwatch on that fact alone.
I think we can objectively say that Tank is less popular than DPS, just purely based on queue times.
I look at it as giving main tanks and offtanks similar firepower. But the offtanks have higher HP and utility, and the barrier tanks have Barriers.
Similar to how there’s offhealers with high sustain/utility, and main healers with raw heals.
And sure, maybe I don’t know much about Tanks in MOBAs or MMORPGs.
But I’ve got decades of class based shooters design with all of them having various classes of “Heavies”.
Luckily this is design for what makes Tanks fun in Class Based Shooter games.
Most tanks already win 1v1 against dps. So… I doubt that is the missing key.
I think the missing key is having a freaking ranged hitscan tank because this is a SHOOTER.
I think we can also say that there are plenty of people who enjoy playing tank as well. Balancing based on the mob and what the majority thinks is fun is a terrible idea. Especially when a game is meant to have unique characters with different methods of having impact.
Considering the vast majority of Tank players are offtank players, and the goal is to make BarrierTanks as fun as OffTanks, I think the vast majority of “Tank Players” would approve.
Sure some people might not like it. But it’s pretty hard to dislike getting to do fun stuff and not feeling like your enjoyment is almost entirely dependant on what your teammates give you.
That said, considering when almost all the changes that I suggested get into the game, they are almost always highly appreciated.
And I’m a Tank Main.
You’d think I got a decent sense on how to make Tanks fun.