I only have the kold kutter studs along the edge of the tires. The theory is that when upright, they contact the ice less, but when turning they dig in more. I used them all last winter with success.
The Kold Kutters are a little different than sheet metal screws, as they have a v-notch, thus are sharper.
I have ‘normal’ studded Schwalbe tires on my mountain bike that work ok, BUT I’ve read that, due to the low tire pressures on fat bikes, those type of studs do not grip as well. But I have no experience with the normal studs on fat tires.
Your thought of using kold kutters along the edge, with grip studs in the centre, could work well.