A glaring and funny historical error in the ending of the Sforza Campaign... (story spoilers)

So basically, the old Francesco Sforza narrates his life story to a young scholar. The guy says many things that are reminiscent of a certain Italian writer from Firenza, such as "oh he should have made people fear him, that's better than being loved" and the such. It's not that hard to deduce who the young scholar is. At the last slide of the last level of the campaign, it is revealed that the young scholar is Machiavelli. But the problem is that Francesco Sforza died 3 years before Machiavelli was born! So this is some freaky time travel sh*t. I'm not complaining, it's just interesting and funny to see such an error. It's ok, we all make mistakes.