A possible way to break down Voynich text

[-JKP-]

Statistically some characters cannot be the same because they appear in very different circumstances. l for example appears in completely different environments than y so I really doubt they are the same. But m appears in many of the same places as y and also looks similar to it in the text - and this is something I only realized after trying to figure out what combinations y could join in.

One has to be careful with such considerations, because it can equally be argued that two shapes that appear in completely different environments can represent the same character, and the two forms are to be used in these different environments as a result of some rule.
This happens with 's' for example (special form at end of word), or with 'r' (r rotunda following a round shape).

The two forms of s don't look at all alike, while the two forms of r have some similarity.

To support and expand on what René said, the letter "u" in medieval documents works this way too.

Just as a midword "s" is usually written as a long-s and an endword "s" is usually written like a "B" or like a Greek "s' (with both having the same meaning), the "u" is typically written like a "v" at the beginning of words but frequently written like a "u" midword.

Or take the "o" shape as another example. If it were in line with the rest of the text, it's the letter "o" but when it's superscripted it's like we say "nd" (2nd) in English OR, if it follows an "m" it can also be the abbreviation for "-odo" (as in modo).


And... to give an example that goes in the other direction...

In Latin, the 9 when used at the beginning of the word means con- or com- but when the same character is at the end, it usually stands for -us (sometimes -os). Same glyph, different interpretation, depending on position.

This "positional" interpretation of characters was very much a part of a medieval scribe's mindset because parchment was expensive, time was always an issue (everything was laboriously written by hand), and ways to abbreviate were as much a part of writing as learning the alphabet.