See, I am a 1 or 3 "!" person myself. 2 or 4 "!" throws off the balance to me. It's like planting 4 bushes in the front of your house. There is no middle. There is no focal point.
You seek symmetry, I seek balance. With four bushes, the focus is on whatever is in the middle of the arrangement. I prefer that the house be the focal point, not the "centered" bush. A bush should accentuate the elevation (or "face") of your home and not be the focus itself.
When the Mexicans tried to put three bushes in front of my home, I insisted on a cluster of four with bookending larger shrubs (a holly variation and a crepe myrtle). I didn't know the proper translation for "four, dammit." Apparently "cilantro, por diem" is not correct.
I eventually got my point across by standing on a spot, pointing vigorously and shouting "el busho, right here-o". My efforts to communicate on their terms clearly pleased them as they went about their work with happy smiles and nods. I even heard them repeating "el busho, right here-o" on numerous occasions as they worked. I felt like we truly connected. But they put six bushes in the grouping anyway. Perhaps my ability to cross the cultural divide resulted in some extra greenery.
When I later oversprayed Roundup and murdered one of the bushes, the symmetry was off and I had to kill another one to make up for it. I like the balance of 2, 4, 6, 8 and other even numbers.