This game isn't for hardcore players

[Kuwagami]

If you think bosses are too easy, when you get into the primal fight, have half the group sit it out and try to beat it with a team of 4 people

Actually some challenges on titan HM are worth a try
like 1 tank 7 WHM

or the 7 sch 1 smn ifrit HM. Both have been realised, yet they prove to be very difficult