For my example above your proposal would produce the following image:
Okay, we all want girls with three tits but with three legs?
Of course this example is unfair, because the scans were made for a tool (e.g. hugin) which requires overlapping arrays to stitch images together, in opposite to "convert" which, as you correctly stated, requires that the scans are perfectly seamlessly. But I can't imagine that anyone is able to produce seamless scans from a magazine, at least not with a flatbed scanner which has no real arrester. Another problem are the different concavities that the two pages usually have.
I think one can only produce a really satisfying result if one disassembles the magazine (to avoid concavities) and spend a lot of time with adjusting angles and drifts in an image manipulating tool.
At the moment hugin seems to have the best result/effort relation for me.