Stacking won''t work because the speakers are too big and they are trapezoidal in shape. The trapezoidal shape when laid horizontally naturally points the drivers upwardard and outward. My screen goes all the way down to the floor and stacking the speakers would obscure part of the picture.
I've read several opinions on the effects of lobing, and like a lot of things here on the 'Gon, there's lots of disagreement on its effects and detriment to the overall sound of your system. Some seem to think the effect is minimal and nothing to worry about.
As for laying a speaker on its side and getting poor dispersion. I haven't had that problem....I get excellent dispersion. A lot of stuff in audio is theory, or it may be factual.....nonetheless, if it sounds good, all the theory and facts go right out the window.
It pretty much comes down to if I like the way the two center channel speaker sound.
I will connect them this weekend and let you know what I think. Ordinarily, I wouldn't even consider two center channels, but my room is out of the ordinary.