Is the check-out just a requirement of a school or club, before they will let you take one out on self-fly hire? If so, then there are no fixed rules, it is up to each school/club.
In practice, at the schools that I have hired from, it is a combination of the school's rules & the CFI's descretion.
So, for newly-qualified low-hours pilot, it is more likely that a checkout on each type would be required, especially if the pilot has few hours on the types to be hired.
Where I hire at present, they require me to do 6 month checkouts on the twin. But for SEPs they are happy for a checkout on a PA28 to cover a C150, or the reverse, but then I do have over 600 hours & fly regularly.