What will make it perfect is that all 20 of them will repeat the same talking points, demonstrating for all the world to see what soulless, robotic, cynical monsters they really are.
And then CNN will cluelessly repeat clips of it to remind everyone, up until they get demolished in the 2020 general.
There is no way all 20 are going to be asked the same question. That would give room for maybe 5 questions, and skip the opening and closing remarks.
This show is for the press to do what it's told, take out certain candidates, and promote others.