That room simulation is pretty good.
I took my calibrated microphone, REW and measured a friends dedicated 2-ch room.
Then I tried the room simulation. Measured the room, listening and speaker position.
I got pretty impressed when I saw the exact bass frequency response! That gave me confidence in that the mathematics behind the simulation were trustworthy.
And as you said it were far easier to move two two bass towers with 4 12" in each tower. Back and fourth to close a dip at 50 Hz in the simulation and in the measurement.
Then it was just to move the speakers to that location.
Not just that I can make the conclusion that the mathematics is spot on. We can also see it the other way around.
That the physics of how the sound reflects/bounce in a room is so predictable so we can use mathematics on it. ;) (Now it were a room of concrete other construction material will absorb/reflect little bit different).