I don’t think you really need to care about the GUIDs. Mendix takes care of it for you under the hood. I’ve seen applications with a large number of records in the database table.
AFAIK, the Guid is a combination of entity id and sequence id. Take a look at this forum post:
https://forum.mendix.com/link/questions/95102
NOTE: I assume you’re referring to the Mendix Id field here which is not directly available for instance in a microflow and which it uses to maintain associations etc.