When I first started... my first FTO was day shift in the slowest possible beat we have. As you can imagine, I didn't learn much. My FTO wasn't very motivated to show me anything that might prove useful later such as paperwork or police work.
I did however get to be on a first name basis with every firefighter in the area.... we had the safest firehouses in the state, almost 24hr police protection of the day room couch.
My second FTO worked 2nds in a much busier area. My first shift... DV run with blood/teeth on floor. Arrest made. I thought "Wow, this S#$T is just like on COPS".... then my FTO said, "Go grab a NIBRS and the DV packet". I said, "What?"
Needless to say, my 2nd FTO and I played a lot of catch-up.
I think OP is onto something... starting in a busy area is a great way to learn. I learned very little beyond the ingredients for a perfect sandwich from my time with my first FTO. Being in a busy car for the remainder of my training was invaluable.