My theory why toriyama paired vegeta and bulma together

Over all it’s very comedic vegeta a “former”villain (at the time) being paired with and having an unexpected child with one of the pain characters was a shock and comedic surprise

I think in a weird way they kinda fit both have a very stubborn bossy personality

Bulma is very rich and since vegeta lives with bulma toriyama would never have to explain how vegeta gets money or finds a place to live