You are all wrong.
There are at least two different private keys that can be generated, one and the same public key and everything related to it, to the address itself.
But, in my opinion, there are four different such keys. Which can form all the same.
I believe you are confusing deriving the public key from the private key and deriving the address from the public key? But even in that case it'd be unlikely to have more than 2 public keys map to the same address.