^ That's an idea. My concern with to jumping straight to the use of external mics doesn't involve any difficulty in using an F3 as recorder, but rather all the other stuff involved- setting up the mics in mounts on a stand in the right way, connecting and managing the cables, getting all that into the right position, not creating a trip hazard, all that jazz.
If you determine external mics and and F3 (or whatever) is the right answer, but want to avoid all those hassles, you might set everything up semi-permanently on a single mic-stand INCUDING the recorder, use a Shapeways mount that has no provision for changing mic angle or spacing (thus eliminating the possibility of any accidental change of mic config), and tie-wrap all the cables neatly to the stand. Make it is so that he can just pull that contraption out of the closet, place it wherever, point it in the right direction and hit record.
FYI this is pretty much how I manage to run 8 channels of mics myself with quick easy setup and breakdown. All the mics in the array remain attached and wired to the recorder at all times. I walk in, assess the situation, put a stand down and attach the array to it (or attach low-foot or clamp), unfold/telescope the array, confirm that the mics are all oriented in the right directions, raise the stand and press record. I can manage all that in about 60 seconds if really pressed for time.
[edit- Now if I could streamline the post work in a similar way.. ]