the best answer to this would be from an FM+OB fellowship director. Note: FM+OB fellowship directors are ObGyns. (Note: grantors of surgical privilege for c-section at hospitals are ObGyns.)
how about let's pick the comparison at 150 c-sections. when you've logged 150-200 c-sections you're pretty much in the game to *ask* a hospital to sign off on you for c-sections as primary.
an obgyn resident hits 150 c-sections by the end of PGY2, after maybe ~6 months clocked on the deck plus call. usually obgyn residents stop counting because they're so far over the minimum at some point in PGY2 or 3. by c-section #50 or so, the attending probably doesn't bother to scrub. that obgyn resident at 150 is going to clock several more months on the deck plus call, with 1-2 more years of residency, usually in a fairly high risk facility. i would expect a PGY4 obygn resident to be able to cope when some serious **** hits the fan in the OR, because of the sheer number of hours that PGY4 has spent in the OR, usually at a high risk center. i would expect a PGY3 or PGY4 obgyn resident to have substantial surgical skill because of all the hysts and onco and general uterus-related carnage they're doing when they're not on the deck.
an fm resident is going to get 1 month, maybe 2, per year, on the deck, and then goes back to med or peds or ortho or what have you for months and months. a bit more deck time on call. a bit more deck time if there's a c-section pager and a willingness to carry it after you do your 12-16 hour shift elsewhere in the hospital. most of the deck time is vag deliveries, not c-sections. the FM grads who hit 150+ c-sections by the end of 3 years of fm residency are not primary on most, and get there by not having any obstacles such as FM+OB fellows, pissy attendings, low volume, competition from other residents, etc. no fm residency is going to guarantee you all the c-sections you want. So the real c-section experience, the predictable accumulation of skill, is in a one year fellowship after 3 years of residency where you're pretty much on the deck all week long.
Anecdotally, a young FM doc who did an OB fellowship and was on FM faculty at my med school, with deck privileges, then started ObGyn residency...as a PGY2.
If there are magic turf wars here, the ObGyns live on that turf 24x7. FM residents *don't* live on that turf. FM residents *visit* that turf for 3 years. FM+OB fellows get to live on that turf for a year, which is the most concentrated time they'll ever have on that turf. A facility that hires an FM+OB doc expects a whole lot of FM out of that doc.
^^ this is how much I've figured out 4 months into FM residency. a year ago I probably would have tried to make an equivalency argument too.
