Octavian/Agustus was supposedly a total milquetoast and was prone to frequent illness, particularly before a battle. Agrippa's victories placed the yellow bastard on the throne.
Claudius has some sort of palsy, stuttered, and even had a drooling problem. Zero luck with the ladies. He was a 1. Everyone thought he was a tard, so the previous two bloodthirsty lunatics didn't bother offing him, and the Praetorian Guard declared him emperor after eliminating Caligula.