Well you said the only person who will have a gun is the bad guy. I know it takes 2-3x longer in NYC to get a gun but if you want a gun to carry in your car for self defense in NYC you can get one, especially now sC struck down the more restrictive requirements.
You mentioned an armed robbery which means the guy attempting to rob you has a gun and is threatening you with deadly force. Both in Florida and NY you can use deadly force if you feel an imminent threat of deadly force to be used against you.
I would say a guy trying to get into your car with a gun counts in both states.
Indeed, I am conflating the two bits. The legal use of deadly force and the ease of getting permits are two separate issues between those states.
The EASE of getting the permits across those three are vastly different, just like the deadly-force-use cases between the two states.