I’m afraid you are talking not about concepts, but about certain implementation details and I’m not sure what is your target and it could be too verbose.
If we are talking exactly about swagger-to-graphql, then you can not link resolvers cross types. It’s not going from the box. The relation is: endpoint — type. It’s built automatically basing on Swagger schema.
If you are worry about amount of requests, then your query can contain request to multiple types. Furthermore most of GraphQL clients support batching of even multiple queries.
I’ve already listed client advantages (just missing that you can also choose which exactly fields to query) in the previous comment.
And I still see, that your concern is in data structure, but not in the delivery method to client.
The main reason, why we did it for our project was a very cool client cache concept, which is not possible with REST.