Doom is a lot more over the top than Luthor. Doom actually reminds me of villains like the Daleks.
Cybermen-"we are five million. How many are you?"
Dalek-"four!"
Cybermen-"you would defeat the Cybermen with four Daleks?"
Dalek-"we would defeat the Cybermen with one Dalek! You are superior in only one respect: you are better at dying!"
That's how Doom sounds, that seething arrogance. Lex is much more subtle.