My opinion is that if you have only two dps, then yes that setup would work.
But in terms of damage, the wedge formation with the highest attack character at the front, assuming the extra hit and damage bonus is based on how many people are in the formation, would technically surpass winged formation by far for damage.
Then again that formation would pretty much mean everyone would get hit, assuming most bosses attack in a conical pattern.
I believe how much the formation buff works is based on how many people (or even stats) are in the formation, it wouldn’t be right if centurion starts a winged formation for the full buff and dps simply stands behind the mob getting the back bonus.
Answering your question, the idea of formation basically restricts movement and skills of other characters. So unless your other dps solely rely on basic attacks, it doesn’t seem viable, and most likely they’ll just jump in and out of your formation to cast their skills as well as to evade the boss attacks
Then technically, as a tank, the formation would be irrelevant since you are still supposed to aggro and maintain a certain guard. As you would not have other formation skills to adapt, then centurion imo is rather pointless.
The ideal tank build would be Swordsman-Peltast-Peltast-Rodel-Rodel-Rodel as a permanent sword and shield user with ability for status effects. I prefer status effects over Centurions defensive stances because of how things seem to work in the game, where status effects affects bosses. Besides, there seems to be a cooldown for centurion formations so I don’t suppose it can work in a traditional party for it to adapt.
Of course, I’m basing this opinion as to what I know of how formations work. It may or may not change in open beta, but I don’t think that a tank or in fact any singular traditional role would work in this game given that boss attacks are either AoE or penetrating. And assuming swash buckling does not keep aggro forever, the only attack you’re really tanking is the melee, which anyone can do with a shield.