Pretonic laryngeals in roots

I may be wrong, but it seems to me that the posited laryngeals in
roots of the form *HCVC occurs in only two functions: as *He-, in
which case they appear as the 'intended vowel' (which is the one found
in Greek and Armenian), and *H-, in which case they disappear (in the
other languages). Would it be possible to posit a vowel instead, with
suitable rules to achieve the same result?


Eg. *édons, *déntm etc


Torsten