I also think that in late medieval/early modern Europe including Russia, a blatantly under-equipped lowborn soldier fighting in an actual battle line was a rarity if not a complete fiction. I mean, heck, when random burghers, gentry and peasantry was raised as part of the National Militia during the Time of Troubles, even they had standards of equipment. The only way you could enlist with no armour in a 1600s militia in Russia at its nadir was if you were an arqueboussier and had your own gun, your own powder, and your own sword.
Ah, this "National Militia" thingy is rather tricky because the ...er... "patriotic picture" does not necessarily correspond to the reality (it HAD to have a broad national base which means that you have to put peasants and other patriotically-minded volunteers into its ranks

). The people who organized the 2nd Opolchenie were practically minded and preferred a relatively small army of the professional soldiers to a bigger unruly mob of a questionable quality.To get the high quality troops you needed to pay them well no matter how patriotic they were. So the whole thing started with a huge fundraising effort to finance this armed force and to provide its loyalty to the cause (*).
As a result, the salaries of the ordinary streltsy and the members of feudal militia (all these service people had been fitting into the traditional categories) were on a level of the pre-war salaries of the Tsar's Guards. Of course, these people had been professional military: the sources are clearly talking about the "service people" from Nizhny Novgorod and other towns (Arzamas, Vyazma, etc.). By the time of the Battle of Moscow (August 1612) the army consisted of 1,000 streltsy, 4,000 cossacks (mounted and on foot) and few thousands of "dvoryanskoe opolchenie".
It looks like on their way to Moscow they were joined by some impoverished people (cossacks and not cossacks) but as a minimum these "naked" and "barefoot" people had some kind of a firearm
«мнозии ж от казатцкову чину и всякие черные люди не имущие… токмо едину пищаль да пороховницу у себя имущие»,
«ови убо боси, инии же нази»
Taking into an account that this army was approximately 8,000 strong and managed (granted, with the help of 2,500 Cossacks) to stand up to the Polish relief army of approximately 12,000 (including 8,000 Cossacks and 1,500 infantry which included 400 Hungarian and 200 German mercenaries) led by no less than
Jan Karol Chodkiewicz and 3,000 Poles as garrison of Kremlin, it should be quite professional in its composition.
The Muscovite state had so-called "
Посошная рать" - auxiliary troops raised from the cities and villages based upon certain quota armed and supplied by their communities but they were used for the construction works, help to the artillerymen, guarding the fortified border lines, etc. but not a battlefield deployment. I did not find any mentioning of it in connection to 1612.
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(*) As was remarked by a disrespectful author of the early XX, if the people had been pawning their property to get the required money, there were also the people
to whom they were pawning the property.
