First of all I liked your definitions.
Second, If I were to define space making i would go with…
The ability to get new space and/or protect existing space.
Tanks first of all need to reach the space they want, and then stand their ground using both damage and protection.
the protection combined with their high hp makes it harder to force them back, and their damage acts as an extra punishment, if you don’t respect their space you will die. but if you do you’re not gonna get harmed.
Winston for example choose space with jump pack, drop bubble to cancel the impact of enemies. and then use his primary to force anything inside the range of the bubble and bit further to get away.
If Winston will try to chase a target he’s most likely gonna die without the bubble since his range is so short and his body is big.
While most tanks claim new space and protect it, some just want to keep the space for themselves. like Orisa and Hog that prefer to keep as much space as they can.
I see the damage tanks do more for punishing resistance in their domain.
B.O.B is an interesting concept similar to charge- you force enemies to move or die. But after it hits a team member or a wall he becomes a normal dps with high hp.
I believe tanks protection is something pretty important since you don’t only make space for yourself but for your own team as well.
I would say a lot of this split depends on synergy.
Bastion for example does the most damage in the game, so a team with the hero never lack damage.
But what he got in damage he lacks in survive ability.
So a protective tank is more important.
I do think protection is something every tank needs in order to split the dps role from the tank role.
but the protection can be higher or lower depends on the amount of things it block, how good it is and overall how much protection the play-style requires.
So if to conclude my definition for a tank.
- High hp
- Some sort of protection: can be something strong as a shield or weak as damage resistance but there’s should be some sort of protection
- The ability to get new space or keep old space safe.
all 3 (although part I can combined with 2) combined making a hero that acts like a wall.
letting your team get near it and get the right place for them to get easier kills.
tanks enable your team to get to the right position for them to get as much value as they can from their kit.
So in a way another way to look at off tanks and main tanks is creating new space vs keeping the space you’ve already got.
Just want to put more emphasis on the damage.
Rein,Zarya,Hog,Sigma can’t do anything if the target is too far.
Winston,D.va,Hammond can’t do much if the target is close but not close enough.
Orisa can’t do much if the target is too close.
Each of them use the damage to punish enemies that came to the range they try to claim/protect.
Because of that I don’t think tanks should have the potential to instantly kill (in time, not abilities or damage. A tank can still get a kill using 1 ability if it takes time to use it and do it like Hammond’s combo or Rein’s charge)
Securing kills is the job of dps.
Tanks are just there to punish.