Gunbreaker breaks my heart

[Shurrikhan]

Except those games are shooting games which use large-scale obstacles as shields, alternatively damage redirection. There are also many tanks that cater to the other side of what a "tank" is. As in, hard-hitting, tough characters that don't actually help other members. Except by happening to be in front of them.

I think you'd have to avoid much about the game to come to quite that conclusion. There is no direct damage redirection among the tanks, for instance, but there is huge toolkit potential by which to open up the opportunities of non-tanks (however indirectly) and -- just as importantly -- decent threat, precisely because threat is what creates safety every bit as much as a barrier. A barrier prevents an action, forcibly, by denying lines of attack. Displacement prevents an action, forcibly, by denying lines of attack. Threat, however, prevents the (perceivable) viability of an action, and can ultimately act as either of the former, forcing enemies into ambushes and/or denying them space.

That's to say, however, that OW's tanks have sole proprietorship over these forms of manipulation -- that's precisely the point. Every "role" in some way manipulates -- through intimidation or feigned weakness, capturing or denying focus -- the position and attention of enemies. Tanks have the eHP and toolkits to push areas that other heroes would be unable to, opening lines of attack against enemy threat, but no role is denied whatever contribution its toolkit would rightly allow. The necessity of one role or another does not exist arbitrarily; it is determined precisely by whatever actions are necessary to win the fights given the time, enemy space, enemy charge, and enemy composition.

I feel like that's ultimately the direction XIV needs to go in if they want their tanks to at all feel like tanks. We should make and take opportunities, via every role in synergy. Tanks have the unique ability to make opportunities otherwise much more easily deniable -- not by rigid mechanic or some gimmick, but by diminished necessary caution (and therein waste of potential throughput) in the context of the actual fight. They do not need, however, to be the only thing an enemy force wishes to attack. Giving tanks passively reduced vulnerability to damage atop the ability to funnel all damage into them just takes away from what tanking ought to be about -- supporting through opportunities granted. Rather than having to know what your team most needs, and when, you simply pay your tax and let the system cover (read: invalidate) the rest. That's not to say that every fight ought to be overly complicated due to doggedly efficient or unique AI, but when the game boils down to just a scripted checklist of enmity and proceed as per striking dummy rotations, etc., the game boils down to a flavorless mush.

As for the phalanx, I'd say that you should know that if you're to correct that, you should say that the Romans legionaries formation was no longer a phalanx (but derived of one), not latch onto that word and imply I mentioned the Macedonian one.
Especially when searching for Roman Phalanx in Google obviously shows plenty of the relevant content.

Except the phalanx was never a name for an interlocking shield technique so much as, very specifically, a unit of long-reach infantry. It's literal meaning as the "fingers" of the army refers no only to its array, but also it's reach. The Romans rarely ever incorporated phalanx into their armies, and certainly never by name except when specifically using Greek (where since conquered by Macedonia) and Macedonian troops. It follows the same pattern as Hussar or Sarissophoroi/Prodromoi. We could metaphorically use either unit's name to describe what they did or was prerequisite to their being effective, but ultimately each was a name for a unit, conventionally sized (even if that convention was to have little convention at all, in the case of the Hussar), of a particular troop type. The pictures that surface in your link are misnomers. They are quite clearly of the Roman Legion (or, Maniple, as in manipular formation), and while there was certainly some derivation -- in the way that all to-be conquerors tend to learn from those who had conquered before, they were also a fundamental departure from the phalanx, favoring versatility and opportunity over fielding reach.