I don't think Vegeta clears Dragon Ball (Pre Z)
I noticed when people discuss what if Vegeta was sent to earth they always say he clears until he around the Saiyan/Namek Saga. In my opinion, I think his mentality when it comes to the fights early on is more important than what people may think. My biggest issue is how his wins are discussed, as if it would be a one off stomp because he blitzes but, that's literally based on the notion he's operating like how he did on Namek. On Namek, Vegeta had the mentality of someone in survival mode. He understood the threat the army posed and played dirty to get his kills. He attacked when their groups were separated (Dodoria), jumped in fights(Freiza), and even sneaked kills(Guldo, Burter, Recoome).Those quick one off blitzes do not happen after this saga, his mentality changes, his survival instinct is replaced with pride and overconfidence. He lets Android 19 absorbs his ki, and ultimately lets Cell become perfect. Later in the Buu Saga, he quickly finishes off Pui Pui but, only to hurry up to fight Goku. Overall Vegeta, albeit along with the other Z fighters, were overconfident vs the threat of Buu and caused more problems. Overall, this mentality would be present if he was on Earth and not raised under a tyrant like Frieza. He would be overconfident and would allow attacks to hit him, like Monster Carrot's Magic Touch (if he never sees it first), Tao Pai Pai's Dodonpa, Devilman's Devilmite beam, General Blue's paralysis, shit even in a scenario against the Mafuba. Vegeta gets defeated because he would chose to stand there and take the hit to humiliate the opponent.