I might take a different approach, having done radio production for may years.
I'd agree that if scheduling allows, have everyone together in one room if it is big enough. By that I mean that it should be acoustically absorbent enough so that reflections should not be a problem.
Mic choices will will be important, first for polar pattern, then for matching the sonic qualities of the mic to each voice.
My first plan would be to use figure 8 mics since they have near total rejection from the sides. I'd then place the actors in a very wide arc, so as no two are facing each other. Alternatively, I would choose either cardioid or hypercardioid mics matching their off-axis rejection angles to the actor's positioning for maximum rejection.
The narrator should be able to see everyone, and they him or her.
I would record multitrack, one for each actor, so you can adjust each actor's level, EQ, dynamics, etc. independently in the final mix. It also makes alternate takes by individual actors easier.