sh_ and ch_ compose the same words

[Davidsch]

Let me ask you Torsten, in your view, could you answer :

from the medieval manuscript viewpoint, for a random hypothetical invented alphabet

If we would use the letter c similar to the letter k, but have a slight preference for one of them,
would you then more likely see if they are 

a) different
b) they behave similar

c) neither

I would expect that both letters are interchangeable and that in one context letter 'c' is used and in another context letter 'k'. It would for instance surprise me to see multiple instances of 'color' and 'colour' in the same paragraph and I would find it stunning to read 'color' and 'colour' along with 'kolor' and 'kolour'.

I thought you would say that. If we estimate the level of experience and intelligence of the author of the VMS to an equally Medieval text, you will find that such written text, at least in the occult genre, are very inconsistent and much words are used inconsistently.

You will very frequently find in the same text, that every possible variation is used, color , colour , kolor, collor, kolore. and such.

We can not draw conclusions based on (in)consistency on a compact level, but we need to look at the big data.
Fortunately there are many pages and many examples, and decision making based on the paleographical elements in the VMS (the specific strokes) or the spelling of words, in specific instances will only allow us to make logical decisions, if we also look at all other instances.

For example if we see ok-chor- everywhere and find only 3 instances ot-chor, we can simply assume those 3 times were a slip of the pen.
(ok-chor and ot-chor have almost an equal count, something like 18 and 20, which is very usual for these ch-sh words)
I understand this is difficult to work with, because exact numbers and edit distance must be applied based on subjective findings, and not on hard numbers,
but it is the only way to come to the ultimate code-set for the VMS.