between John and Harry

[azz]

a. Between John and Harry, there are two people who say that they have seen you in Jeff's apartment on the night of the murder.
b. Between John, Pete and Harry, there are three people who say that they have seen you in Jeff's apartment on the night of the murder.

In (a) the two people are John and Harry. In (b) the three people are John, Harry and Pete.

Are (a) and (b) grammatically correct with those meanings?
Is that usage of 'between' legitimate?
Is it slang?

c. Between Henry and Tom we had two people to do the job.

In this case, the two people we had to do the job were Henry and Tom. Is (c) grammatically correct?

Many thanks.

[Darryl]

'Between' just doesn't work for me in that context. Perhaps there are places where it is used colloquially in that way, but it does seem odd. I don't see the need to use 'between'.
Just:
John, Pete and Harry are three people who ?

[admin]

I agree. You might use between like this...

When talking to three children who have been playing in the mud: Look at you three! You haven't got a clean pair of knees between you!