you can seperate them ofc by using the models manager an the query object. i've built a stateless service architecture fir interacting objects but these are design decisions and based on taste.
check the phalcon dev tools for that
since it's an active record concept and you wanna turn it into a data mapper concept the answer is : just name it so it makes sense and think about the structure before you implement it.
i hope this is helping a little :)