I came. I saw.
I lost miserably.
The short answer is no, you may not have duplicates of characters. My RGG edition says on page 4, paragraph 2 that the only duplication allowed is the Fool/Chatlatan
Can you have 2 Fools? I thought the second time you got nothing useful the Fool switched to a Charlatan. As a result, you can get 2 Charlatans but not 2 Fools.