(2) player content

[Wildsprite]

This is not an issue, DCUO for example, has duos. 2 dps is actually optimal for these instances as you can burn everything down fairly quick.

A healer for example is a plus but not needed. Nor is a tank, the ads in these instances will be completely manageable by any two role combo.

Though as I stated before, obviously 2 healers will see a longer run time.

Its not about what roles are viable, because they all would be.

you could try being more specific, WHM does great as a DD for burst damage. SCH does DoTs and low burst damage. both are healers
WAR does heavy damage to keep hate where as PLD uses other methods and does not. both are tanks
so WHM and WAR or 2 WHM or 2 WAR would rip through these pretty fast where as a duo of SCH and PLD probably would not.

ofcourse if they made it so there was some dynamic to make up for the lack of burst damage by some classes/jobs

for instance for low burst damage jobs some dynamic is added to make it more interesting such as some sort of puzzle.
or make the reward base on how much your class/job is capable of. lots of possibilities on that