Re: the favorite actor or
My wife and I have the same favorite actor.
Five of my my students have the same favorite actor.
Joe Smith is the favorite actor of five of my students.
Joe Smith if both my wife's and my favorite actor.
There are many ways to say this. Some are grammatical but not natural.
Some are natural but perhaps not completely grammatical.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.