I thought of a stupid powerful duo combination: Flintlock with the Invincibility Trinity (or maybe Trade Off and Playing Dead with Energy Charge) + homing Eyetracks with Slip Shot, Quick Charge, and Energy Charge.
The Flintlock can easily FRONTLINE because of the invincibility powers in combination with being able to 1HK at FREAKING TWENTY METERS, when defense weapons simply have problems with the Eyetracks spammage to begin with. It will ensure that nobody will EVER get close to the Eyetracks so easily at all.
Here's what would happen:
*Eyetracks Slip Shots like crazy. The spammage combined with Energy Charge will destroy anything that refuses to approach.
*Naturally, when the opponent's approach, they have to deal with the stupid strong Flintlock who can 1HK people even at close range. If you think that 25 Staff Melee Strength is going to kill them, think again, because as soon as you get close, they'll just use an invincibility power and laugh.
*Now if they use Playing Dead, you think you can just get close to them so that they would inadvertently melee if they try to attack, but then the Eyetracks guy will just rip you apart. If you move away, you'll get shot from behind. Either way, you're dead.
*And in the case that there's two of you? Simple: the Eyetracks will stay near the Flintlock. If you try a flanking attack, divide and conquer will silence your ability to stop the Eyetracks from escaping in a hurry.
So. Dumb. And I haven't even thought of who would fit in for the third player, though I'd expect they'd be providing backside cover to end ambushes on the Eyetracks.
Let's compare to my post last week:
I saw the tank as more of a bodyguard figure for the sniper though, with the third teammate acting as a focus of sorts to draw the battle to him (a status-based Viridi Claw or Phosphora Bow would do well) and draw out potential targets for the sniper. The sniper effectively is "with" both the other teammates, so nobody's really being caught alone. Not an invincible comp, just a basic strategy.
One powerful ranged DPS? Check.
One bodyguard? Check.
The only difference is that you suggest a second bodyguard to make a deathball of sorts, while I suggest a harasser/"focus" to keep them from making any sort of coordinated attack on the other two.
There is nothing new under the sun.
But why use Flintlock as the tank? There are a billion better ways to go about the strat.
For your version, I'd use Magnus Club as the bodyguard. The only way you can really best a Magnus Club is by kiting it; and if you're kiting the Magnus, you aren't going to be able to also deal with the Eyetracks. Meanwhile, if there's two players going after the pair, all Magnus and Eyetracks have to do is target the guy that's targeting their buddy.
Almost anything can make a decent third for this strat.
Additional snipers enable you to cover enemies coming in multiple directions.
Another bodyguard basically makes you a deathball.
A harasser keeps the enemy from organizing against your duo.
The best counter for this strat is an enemy sniper. If the team sniper doesn't focus them down on sight, they can pick them off before the tank can react.
Of course, this is just one paradigm. Something like triple Claw would work totally differently.