For a bit of context, here's how the "Mobilization" was supposed to work, back in Soviet times:
The Soviet Army broke their forces up into 3 (4, really, but the last two sort of merge into one at the boundaries) categories: A, B, C (I, II, III in some NATO/TRADOC docs). These categories were based on the manning and equipment readiness of the unit.
A (or I): Fully-manned (realistically, 95-100%) and fully equipped with modern systems. Fully ready for operations.
B (or II): 50-75% manned, with a complete set of fighting vehicles and weapons (possibly lacking some support and specialist systems). Still capable of operations, generally regarded as needing at least 72hrs to spin up. Missing personnel would be made good with loose/TDY/reassigned personnel (from training/staff units, and units that are redundant during wartime) and personnel pushed out of training early.
C (or III): 10-25% manned (cadre, IOW), with a full set of combat equipment...but that full set might be a generation or two behind what a Cat A (I) division might have (this is where we'd see the T-55s and T-34's turning up, back in the 70's and maybe 80's). Not capable of operations, and needing at least two months to spin up (and, allegedly, significant equipment and vehicles transferred from the civilian sector). The majority of the personnel of the division, once fully mobilized, would be either recalled Reservists* or hastily-inducted Conscripts
We'll turn our gaze to the last Category (C, which includes also Category D, which were units that basically existed only on paper, with maaaaybe some small personnel and equipment establishment or contingency plan).
Category C would be the late war (and by "late", in WW III terms, we mean D+60 or so, when the Regular and best-of-the-Reserve forces of each side had beaten each other to death, and most of the high-tech platforms and ammo would have been expended) reinforcements, made up of raw conscripts and "old guys"/"Reservists" (recalled ex-Conscripts who might have been a decade or two out of uniform), led by cadre officers/warrants, using older gear (ironically, the stuff the older ex-conscripts would be familiar with from their time in the Army), and with TUFT (Taken Up From Trade, i.e. mobilized civilian) logistics/medical/support capacity.
The principal being that a barely-capable, technically-obsolete division is a lot better than no division at all, when it ambles into the AO. If the Enemy can't come up with anything equivalent....you win by virtue of being the last man with troop units.
The Cat III reservists who showed up in Prague, in 1968, took three weeks to arrive (from the day they were informed of their recall)....and lacked uniforms (but had tanks and AKs).
What's happening now, in Russia, with this "partial mobilization" (that's sounding increasingly less partial as the info flows out)....is basically building up the Cat C divisions.
PROBLEM: the professional apparatus and infrastructure that let the Soviets make this sort of thing work no longer exists, and hasn't existed for about 30 years. The current Russian military isn't capable of managing this. Nor does the Russian military have the Everest-sized mountain of slightly-used gear (and ordnance) that the Soviets could easily dip into to give shaky "old dudes and kids" units the firepower and protection to counteract the shakiness. Nor is the Ukrainian force utterly exhausted, such that they won't smash a third-line division off the map with modern weaponry and NATO-enabled C4I.
Even formed Cat C divisions, with established command echelons, would need at least a couple weeks (not the individual personnel....the actual division) of shaking out before they could semi-reliably conduct even the most basic (area security, etc) operations. I doubt these units (and it seems only some of the recalled/conscripted guys are going straight to active units) had command/leadership staff prior to last week. Not to mention a chunk of those guys apparently never served before this, so have zero training to fall back on (even guys with 15 years between their grunt days and now are useful, in that they have somewhat of a clue as to what's going on and how things should work).
*-The Soviets, and Russians afterwards, have never had a real Western/US-style reserve component. You got done with your mandatory conscript service (or retired from active service, or just completed a very-basic officer training in University) and went into a mobilization pool. No refresher/drill training (it did happen, but rarely enough that most ex-conscripts never got any), just a periodic update to keep the local military commissariat informed as to your location and general state of not being dead yet.
Carried over from SB with the addendum that the Russians seem to have cannibalized even the cat C training cadres./