After thinking this through and looking on what I wrote, I agree on what you're saying (if I understand you right) AND what I'm saying.
Let's look at what I said, /w comments that explains what I meant. And folks, this is just an example. Real life example though, from our first three album recordings in Studio Fredman.
1A - 100% L - ENGL amp
1B - 100% R - ENGL amp
2A - 80% L - 5150 amp
2B - 80% R - 5150 amp
1A and 1B does not have to be the same part doubled, but they have to have the same sound to make the overall sound balanced. An alternative is to make 1A and 1B exactly the same, and make the L/R variations and harmonies on the 2A/2B tracks. All this is IMHO of course.
On our last album, we just used a 5150. 1A/1B with one guitar/amp setting, and 2A/2B with another guitar/other amp setting. A few full songs here if you wanna hear it:
http://www.myspace.com/thestorytellersweden