Don't you want perfect balance?
You are approaching this from the HiFi angle which is where Garnet came from in the beginning as well. These roots are why Garnet amps use the Baxandal style tone controls, any HiFi builder worth his salt stays away from those wonky Fender tone stacks. For guitars, tho, they work. Same with the split load phase invertor. Because it takes careful tuning to get the phase amplitiudes equal and no matter what you do the output impedances are not going to be the same (affecting frequency response) it is, IMHO, a poor choice for HIFi work. However, for guitars, any source of harmonics is probably good. Especially if the top and bottom of the signal are affected differently; ie a poorly balanced PI.
Don
PS If I called them RCA instead of Baxandal style, would everyone know what I was talking about?