Exactly!

NEWID() creates a unique identifier.

Is it randomly distributed over as set of charater strings of certain length, or something like that? Otherwise, it is not clear RAND(checksum(newid())) is unformly distributed...

To "chose at random from 1,..,5" usually means to chose from 1,..,5 in such a way that any outcome has the same probability of being selected.

Assuming T-SQL RAND() has good...