When we check the hadith literature we may find out that commentators in first place focussed on the two sahihs and al-Muwatta' which for which one may find much more than ten known (or famous and printed) commentaries, when we move to the so called sunan-books (sunan ibn Majah, abi Dawood, an-Nasa'i) and Jami' at-Tirmdhi we may find less commentaries (explaining in first place the meaning of the hadith content and maybe addressing it's chain etc.) and often the commentators rely on comments of either the sahihs or al-Muwatta'. However I think that one of both sunan books of an-Nasa'i we find out that the book which was (more?) commented is rather his as-Sunan as-Sughra (the small sunnan) than as-Sunnan al-Kubra (the big sunnan).

Of course many efforts and books have surely disappeared! So we may miss a lot of the efforts of early scholars.

My question is are there any known commentaries on other books (Examples to make a kind of focus) like:

 - Musnad Ahmad.
 - Musnad ad-Darimi
which would complete the 9 sunnan books and

 - At-Tabarnis three encyclopaedias (al-Majma' as-Saghir, al-Majma' al-Awsat, al-Majma' al-Kabir)
 - Musnad al-Bazzar.
 - al-Mustadrak of al-Hakim
 - as-Sunan al-Kubra of al-Bayhaqi
 - Musanaf ibn Abi Shaibah
 - Musanaf 'Abdurrazzaq

which might also be rather known. There of course much more books which are more or less known like the musnad's of a-Shafi'i, abu Hanifa many books of ibn abi Donya and ibn al-Mubarak.

If there are not it would be nice if you could provide an explanation why this is the case?

To give the other case more of a focus: An answer would be satisfactory if you could at least provide some titles commentaries (more on the content) of Musnad Ahmad and Sunan ad-Darimi.