Well it is not like dragoons only put on piercing buff. They also give crit too and the shorter a fight is, the higher your dps will be. either way, the math is not completely irrelevant to the topic of discussion but it is not the focus.

It's just my opinion that the piercing debuff accounts for way too much of bard DPS. I do not exactly agreee with dropping it to 5% but they will probably be compensated for it.