Yes, it is possible to do what you want. For decades people have been splitting their Access databases apart into multiple databases. Mostly because it helps stabilize a multi-user environment.
Typically, one database is split into two databases where one is called the Frontend and the other is called a Backend. The Backend is the one that keeps all the Data and Queries and the User interface (Forms, Reports, macros, VBA code) is stripped out. The Frontend database is the opposite of the Backend and is where all the UI elements are stored; it is the application that the User actually runs. When the User runs the Frontend, it is linked to the Backend's data and the Forms and Reports use this Data just like they would have before the database was split.
You can do this as well, but instead of having one Backend database you would have two. Probably the greatest task you will face is the merging of the two Frontend databases into a single Frontend. I would take it a step at a time and Split one Database so you can see what you are dealing with, then I would split the second database and start moving the Forms and code from the Second Frontend into the First Frontend while reworking your switchboard.
This link has quite a lot of information you might want to read over before you start making modifications.
https://bytes.com/topic/access/insig...ront-back-ends You might not need all the information that is provided if you aren't deploying your Frontend, but knowing about it now might help you as more people start using your database.
And as always when working with Access Databases, make backups. Make a backup every time you plan on making a major change. Make a backup every time you make a minor change. Make a backup every day, twice. Make a backup every time someone in your office sneezes.