Loprieno on Middle Egyptian Vocalism

After reading Loprieno's version of Middle Egyptian in Ancient Egyptian, I have some reservations. While there is no doubt that his book is chalked full of knowledge and facts about the Egyptian and Coptic languages, I can't help but think that the vowels in Middle Egyptian could be reconstructed a little better. In some cases, his reconstructions even seem a little, dare I say, implausible. For one thing, it seems to me that there is no point in reconstructing anything but a schwa for all unstressed vowels. Evidentally, based on Coptic evidence, unstressed vowels must have fell together anyway as confirmed by John Collender who writes that this event happened before the Late Egyptian period. Also, it seems to me that long vowels as predicted by Coptic might be explained on the phonetic level rather than the phonemic, based largely on the structure of the Middle Egyptian syllable (i.e. long vowels in open syllables; short vowels in closed syllables).

So, for the past few months now, I've been pompously pondering on how I would reconstruct Middle Egyptian more precisely. Quite frankly, I can't say that I'm anywhere near an expert in Egyptian linguistics yet. However I do understand how languages work and I can't resist exploring new ideas. We can compare Loprieno's version of the Egyptian numerals from “one” to “ten” as exemplars of what dissatisfies me about his reconstructions and what my own mind is instinctively concocting for better or worse.

	Loprieno (1995)[1]	My attempt	Sahidic Coptic
wˁ.w 'one'	*wúʕʕuw	*waʕ [wæʕ]	oua
sn.wy 'two'	*sinúwway	*səna(ʕ)wi [sə'næʕwɪ]	snau
ḫmt.w 'three'	*ḫámtaw	*ḫámətə ['xɑ:mətʰə]	šomnt
fd.w 'four'	*yifdáw	*fədá [ɸə'dɑ:]	ftoou
dỉ.w 'five'	*dī́yaw	*díyə ['dɪjə]	tiou
sỉs.w 'six'	*sáʔsaw	*sisá [sɪ'sɑ:]	soou
sfḫ.w 'seven'	*sáfḫaw	*sáfḫə ['sæɸxə]	šašf
ḫmn.w 'eight'	*ḫamā́naw	*ḫəmánə [xə'mɑ:nə]	šmoun
psḏ.w 'nine'	*pisī́jaw	*pəsíjə [pə'si:ɟə]	psis
mḏ.w 'ten'	*mū́jaw	*mújə ['my:ɟə]	mēt

I presume that Loprieno reconstructs *yifdáw '4' (and likewise John Callender reconstructs *yAssáw '6') based on Coptic --afte and -ase as in mNtafte '14', mNtase '16', jwtafte '24' and jwtase '26'. However, I wonder if this might be the result of an intrusive vowel inserted before the Coptic period, perhaps to avoid accentuation on the final syllable of a compound word since, coincidentally, it appears that both 'four' and 'six' must have had accent on the ultima in Middle Egyptian. Perhaps along the lines of: *mujə-fədá > *mujə-ftá > *mujáftə > Sahidic mNtafte. What's more, if the word 'four' is etymologically related to Hausa huɗu as is commonly understood then it's rather unlikely to me, based on both this and the Coptic reflex, that there was a prothetic syllable in this numeral and probably also in the word for 'six' for the same reason.

Then again, I admit I might be missing some important fact or another so if someone can please explain why Loprieno reconstructs things the way he does, don't be shy to post me a contrarian comment. On topics like these, I rather enjoy academic disagreements over and above homogeneous consensus.

NOTES
^[1] Loprieno, Ancient Egyptian (1995), p.71 (see link).