You can already do this if you convince your DM the situation warrants it.
I don't think that has anything to do with class. It has to do with Charisma. Now if you are a fighter you might use your sword to do that, but it being able to convince those people has nothing to do with being a fighter. Quite frankly it has nothing to do with class at all and a Bard that decided to dump Charisma would not (and should not) be very good at it either.
Hitler did not convince 80 million Germans to follow him into WW2 by talking about a great soldier he was in WW1.