Both Dragon Ball Z and Mad Men canonically take place in a universe that includes Earth, so we can begin by assuming that they share the same timeline. According to this quora answer and this DBZ timeline, Vegeta was born in 1967 by our reckoning. It is likely that Bert Cooper could have killed him at this point in single combat given that Vegeta was a mere infant. However, Bert Cooper died in July 1969, so at the current moment Vegeta would certainly win in a fight against his inanimate skeletal remains.
