Not sure why you would bring in both formats – do not edit with the raw cam files. Converting is the way to go.
You would use easy setup:
1080i60

then set the fields to none

OR
108030p easy setup

and fields to none

Then change the compressor to pro-res if that is what your files are.

Or, drag a imported movie file onto a new comp and let FCP change the comp to match. But if you shot progressive then change the fields setting to none.
Back up cam card files always.
Chris Tompkins
Video Atlanta LLC