It comes down to volume and packaging. If 4x round holes do not have the area, a single bigger one may, area grows quickly with a single butterfly in large diameter.
For stockers, most factory manifolds work a very large plenum in order to run longer runners within that plenum, those longer runners are good for torque, but also smooth the flow entering a port, all the big open TB has to do is let in air, so a big single is easy
In the case of a standard FE intake, unless the 4150 or Dommy cannot flow enough, the standard throttle body will be a better match to all 8 cylinders