Similar with a dead magneto, what happens when the good one fails?
Come on....you have no sense of humour lad!
Read again!
Being serious though, in your scenario taking off with one failed mag and then having a second.....well you don't have to be too smart to work that out.
Compared to a Baron with one failed alternator, and the risk of two dead alternators.....I know which problem I would rather have.
Now back to comic relief!