It seems that there is a consensus that the PIE roots for ten and hundred are, respectively, *deḱṃ and *ḱṃtóm. There also seems to be a consensus that *ḱṃtóm is a shortened version of *deḱṃtóm. These two roots are strongly related, both morphologically (sharing the syllable *-ḱm-) and semantically (a hundred is ten times ten). But what exactly is the nature of this relationship? Researching the subject, I have found some accounts:
Menninger, 1992: *(d)ḱṃtóm was formed by appending the syllable *-to- to the root *deḱṃ, which turned the number ten into a noun (something like "ten-ness"). In other words, the Proto-Indo-European speakers conceived a hundred essentially as a ten-ness (of tens).
Anthony, 2007: *ḱṃtóm means (a unit of) tens. So, the combination of these two morphemes (*deḱṃ + *ḱṃtóm), meaning "ten units of ten", would have given rise to *(de)ḱṃtóm.
Quiles and López-Menchero, 2011: The tens were normally formed with the units followed by the suffix *-dḱṃta ("group of ten"). For example, thirty is *trídḱṃta (*tri + *-dḱṃta). According to this analysis, the word for hundred was formed by *deḱṃ + *-dḱṃta, which somehow produced the word *(d)ḱṃtóm.
These three explanations are very similar, but they also seem to be slightly different from each other. Are they really different or (what is probably the case) am I missing the big picture here?