In 1839, John William Donaldson showed that the
letters of the alphabet are grouped by their phonetic
and articulatory features:

The way Donaldson transliterates ו ,ח, and ט is not
necessarily accurate, but this does not significantly
affect the overall pattern.
He hesitated to include a row for the letters he
called “liquids,” apparently unwilling to alter the
traditional order. This is somewhat
self-contradictory, since he goes on to state —
probably following Tacitus — that “these sixteen
letters constituted the original Greek alphabet”
(sedecim litterarum formas).
In 1883, Isaac Taylor reviewed various explanations of
alphabetic order, including Donaldson’s. Unlike
Donaldson, Taylor did not hesitate to include the
liquids. He moved m among the other labials and
switched the positions of r and k to demonstrate that
the underlying structure is still largely present and
requires only minor adjustments to become fully
consistent:

Here Taylor simply transliterated the earlier forms.
His treatment of the “sibilants” is less clear. Given
the reference to the original sixteen letters, it
might have been more natural to treat ט as a
“continuous” sound (like the Greek θ) and exclude the
others.
What I propose here is an explanation for why the
articulatory structure appears distorted in alphabets:
There is a second, independent structure superimposed
on the first. This second pattern has received
surprisingly little attention in the literature, even
though it is particularly clear in the Latin alphabet
used by most of the world today: it places L in the
leftmost position and R in the rightmost position.
This left–right framing may also explain why the
distortion in the articulatory structure is strongest
among the sonorants (formerly called liquids).
Both structures can already be observed in the oldest
known abecedaries. This naturally raises questions
that I am not yet prepared to answer definitively.
Since M is misplaced in every alphabet I have
examined, it seems possible that the order of the
alphabet was modified before it spread.
Beyond its possible pedagogical value — making it
easier for children or adult learners to acquire an
alphabet or master a foreign script — this dual
structure suggests that we may need to reconsider
certain conventional transliterations of Ugaritic
letters. This is supported by o.6 in KTU 5.14:
It may also indicate that the
Ugaritic sign 𐎓 represents the vowel o,
while the Sumerian sign 𒌋 represents the consonant
v,
making both a likely predecessor of ו, which
represents both sounds in Hebrew.
References:
Donaldson, John William. 1839. The New Cratylus; or,
Contributions Towards a More Accurate Knowledge of the
Greek Language. Cambridge: J. and J. J. Deighton;
London: John W. Parker.
Tacitus. Annales. Book 11, Chapter 14.
Taylor, Isaac. 1883. The Alphabet: An Account of the
Origin and Development of Letters. 2 vols. London:
Kegan Paul, Trench & Co.
Virolleaud, Charles. 1957. Le Palais Royal d'Ugarit
II: Textes en cunéiformes alphabétiques des archives
est, ouest et centrales. Paris: Imprimerie Nationale;
Librairie C. Klincksieck. (Mission de Ras Shamra, vol.
7).