The Voynich Manuscript's alphabet is smaller than you think (and that's why your theory is wrong).
References:
Long-s manuscript example from https://digi.vatlib.it/view/MSS_Barb.lat.70/0021
Cheshire table from: Rene Zandbergen, No News about the Voynich Manuscript? https://www.academia.edu/39733354
Cheshire translation from https://www.researchgate.net/publication/379759411_Astrology_Series_No_4_Manuscript_MS_408
Emma May Smith, The Equivalence of [a] and [y]. https://agnosticvoynich.wordpress.com/2015/03/08/the-equivalence-of-a-and-y-in-the-voynich-script/
License-free stock pictures from https://www.freepik.com/
Hieroglyph Photo by Chris Linnett on Unsplash
Various photos from Wikipedia:
https://en.wikipedia.org/wiki/Dresden_Codex#/media/File:Dresden_Codex_pp.58-62_78.jpg
https://en.wikipedia.org/wiki/Phoenician_alphabet#/media/File:Ph%C3%B6nizisch-6Sprachen.svg
https://en.wikipedia.org/wiki/Chinese_characters#/media/File:%E5%A7%93%E8%A7%A3_Digidepo_1287529_00000014(2)_(cropped).jpg
https://commons.wikimedia.org/wiki/File:Ioanne_Arnoldo_1541_(2).jpeg
https://commons.wikimedia.org/wiki/File:A_Missionary_Preaching_to_Natives,_on_the_lava_at_Kokukano,_Hawaii,_sketch_by_William_Ellis.jpg
https://de.wikipedia.org/wiki/Litterae#/media/Datei:Innocenty_IV_zatwierdza_rozgraniczenie_bpstwa_ryskiego_uczynione_przez_Wilhelma.jpg
https://commons.wikimedia.org/wiki/File:Donation_de_Frederic_II_1_-_Archives_Nationales_-_AE-I-1_n%C2%B01.jpg
https://www.mmdc.nl/static/site/highlights/998/A_childs_alphabet.html
https://en.wikipedia.org/wiki/List_of_languages_by_number_of_phonemes
https://medievalbooks.nl/wp-content/uploads/2014/09/bergamo-biblioteca-civica-ms-cassaf-1-21-hi-res.jpg
https://www.dhi.ac.uk/category/partners/magd/
https://www.researchgate.net/figure/Shapes-of-Arabic-alphabets_tbl1_228983972
"Latin Alphabet" Lion from https://iconographic.warburg.sas.ac.uk/object-wpc-wid-ahcr
Typewriter sound effect fromSound Effect from Pixabay.