I have Theories on that and that is that Johnny is meant to be TS3 Malcolm! They share the Ambitious trait, and I can totally see the outgoing comedian being a sweet li'l bookworm when he was younger. But alas, a Good kid isn't exactly the kind Nancy wants to see as her heir, so he gets booted and TS4!Malcolm comes along to replace him.
(In my main save, that's part of the backstory, actually. Johnny's original name was Malcolm, and who we know as Malcolm was originally Sebastian. When Johnny was disowned, he changed his name, and Sebastian's name was changed to Malcolm, with Nancy pretending that he was their only child, their heir, Malcolm Landgraab, all along.)
Anyway. Conspiracy theories are fun.
Mortimer definitely seems like the kind to find the nearest friendly vampire and go, "Hey, you. Bite me." XD I wonder if it makes it better or worse than the Goth I see Caleb paired with the most is Cass...?
Have a great time on the thread! :D