Interesting. You are saying the VSM-1 will outperform 1Ci for surround!
My target for having a 5.1 surround is SACD and HT.
I think the "will" should be "should, in theroy" just because of the way they are designed.
The reason I say this is because with the VSM-1's the "
coaxial woofer and tweeter share the same acoustical center so they are always perfectly aligned and converge within inches." The 1Ci is designed to be positioned away from the wall where "
their drivers can fully converge and properly align at the listening position", this require about 8 to 10 feet if I'm not mistaken. Also with the 1Ci put into that corner, it will rather emphasize the output of the base.
I use to run that setup with the VSM's, except with a little more space and a 2Wq working in conjunction the VSM's just behind the couch and it worked well, I could run the VSM full range.
I would go with the diagram you have and use something to block the sound from reflecting directly off the wall beside the VSM.
You will not know until you try. And if you get to use them both let us know how it turns out.