What's interesting is if it was one of the three characters you mentioned we as the audience would probably have very specific assumptions as to who they were talking about when telling Poe "I know your kind; impulsive, dangerous and exactly what we don't need right now."
If Ackbar said it we could assume he was saying "we don't need a crazy ROTJ Lando right now."
If Lando said it we could assume he meant "we don't need a crazy Han Solo right now."
And Mon Mothma would have us assuming she meant "we don't need a crazy Jyn Erso right now."
It definitely would have been cool to have that extra layer of context to the dialogue. That said I still am fine with Dern's portrayal of Holdo and the fact that she was a brand new character. But yeah it definitely would have been cool to see how it would have played with someone else as well.
I would still be frustrated when I figured out that ultimately nothing happens and the conflict was nothing more then a plot convenience... But it would have made for much better drama. An established character who made good decisions in the past is far better then some boring silly looking, out of place, character that I have no interest in and does nothing but make the wrong choice each and every time.