No, don't worry at all about answering questions put to others, if you have relevant info!
I've read the same thing about game crosses being great broodies - in fact, I got to hear it straight from the horses' mouth, so to speak, when I had a chance to chat with Harvey Ussery for a few minutes at the Common Ground Country Fair this last year after he spoke on growing your own chicken feed crops. He has some amazing stories about teeny little Game Bird mammas beating up hawks, raccoons, minks, all sorts of predators. Our birds mostly free-range here, though the off-grid place we're looking at is in the middle of 4,000 acres of Nature Conservancy land so they probably won't free range there without supervision - there's a large greenhouse space I'll use as a brooder/broody pen, at least until they're big enough to be warm at night in a tractor grow-out pen outside. I've considered getting some game crosses - my last mixed-breed rooster was a NH Red/OEGB cross, and he was such a phenomenal guy that I let him stand over some of my not-so-pretty Faverolle girls on the strength of his personality and the reputation of OEGBs as broodies alone. My husband, however, loves Faverolles and only Faverolles, and Cloverleaf is the first person I've seen who says her Faverolles go broody regularly - most everyone else I've talked to has had them not be very reliable setters, and even less reliable mothers. Part of my impetus to let Soup (the OEGB mix) stand to the Faverolles was the hope of getting some Faverolle cross hens who would brood reliably and well (and if not, well, their dad was delicious.)
The trouble with getting a second breed as broodies, at least for us this year, is separate housing for the second breed - I would love to get some bantam cochins or game birds. But, Soup ended up becoming his namesake because he COULD NOT live in harmony with the two (much younger) Faverolle cockerels we have. I've never been able to successfully integrate Faverolles with other standard-size breeds, even just a couple of other-breed hens in a big flock of 20+ Favs, without the Faverolles suffering for it in some way, either losing beards and toe feathers, getting chased off the food, bumped to the floor of the coop at night even when they're TONS of empty roosts, etc. Any tips on how to get other non-bearded breeds to play nice with my floofy-faces would be great too!
I would just get some girl chicks to raise out, and put them in w/ the favs at as young an age as possible so they bond and behave well in the flock (I would brood them at coop floor level in a wire dog crate once they were 4 weeks) if they are anything like the cornish mixes my friend has they will lay roundish hard shelled brown eggs which should be fairly easy to tell apart... then just add a few girl chicks to the mix every couple of years to ensure you always have them... older girls make better broodies anyway, and your game hen broodies would be at if for years, maybe a decade or more even.