Assuming both workloads are totally equal,

My opinion is ,
whether he wants to
- Be in a position to learn more (Job1)
- Be in a position to do a good job (produce better end results) (Job2)

Job1 sounds like a good start, as it gives him a bigger picture and would maybe help him decide what he wants to focus on in the future.
But to my experience, handling a project while doing the actual work yourself, leads to some difficulty.

Job2 sounds like a bigger company, as a bigger company normally has more focused job scopes
This focus may bore him, but the quality of his work may be better