Negotiation of a faculty position
FYI I am not in a medical school, but this seems relatively straightforward to me. Hopefully someone will correct if there is a different norm in those departments.

Most departments receive authorizations to hire faculty positions ("faculty [budget] lines") from entities that are higher up the organizational hierarchy, such as a dean or other central administration person. So even if this person is a department chair, they may not have the authorization to create new lines. They may have the authorization to create post-doc positions, since those can come out of shorter term pots of money. 

This person may be implying that a non-faculty (post-doc, perhaps) position would be possible, depending on how much of the budget gets sucked up in the two new researchers' salaries/packages. They seem to think you would not be a great fit for those two new research positions. But they won't know about the post-doc until later. They also assume you will also not be able to decide on this until you have explored your faculty positions, since, for most people, permanent/faculty positions dominate post-doc positions.