So as Russian forces close in towards Kiev I was thinking, it's the capital and the enemy has had a bit of time to prepare, so they probably don't want to got bogged down in urban combat. Surely they are just going to launch a massive sustained artillery barrage over many days, just completely mash the city far worse than they have dolled out elsewhere and basically make it so bad for the civilian population that they expect, perhaps incorrectly that defenders will be left with a lot of guilt if they keep fighting, countless thousands of innocent lives to be taken away unless they put down their weapons.
I'm honestly not sure if the Russians have the capacity to keep the artillery supplied for sustained, large scale barrages.
They seem to be having issues with supplying food and fuel to their troops, and apparently their logistics corps is about half the size of the equivalent US/Western one, whilst a single barrage from one of their rocket vehicles uses a full truck load.
Their logistics setup from what I understand is designed to be working in conjunction with nearby railway resupply not advancing into another country and relying on the road network to keep units supplied, so they've got less vehicles dedicated to resupply than the US, whilst at the same time they're far more "consumable" heavy than the US due to their reliance on artillery, the end result is that it's much harder to keep their heavy/long distance stuff stocked up. That's before you consider that the vehicles carrying the supplies are basically unarmoured sitting ducks to anyone with a fairly light weapons, let alone people with stuff designed to take out armoured targets and you get a situation where every supply vehicle hit massively impacts the ability to carry on.
Apparently their fuel supply situation is even worse because they have even fewer bowsers in comparison to the US, again because their doctrine calls for laying things like fuel pipelines or rail supply to relatively near the front, so every time the Ukrainians take one out the effect on the Russians is amplified as it not only affects the front line fighting vehicles, but the ability to keep the supply vehicles running.
Apparently the Russians also do "push" logistics where the commanders at base decide what is needed according to the plan and send it forward, which is great if things are going to plan, but it means that if they're not, or even if it's going well but you use more of something than planned you can end up without it until command know, acknowledge and deal with it, the US (and much of the west) have much more flexibility with units requesting supplies and getting them as a high priority. It seems to be an offshoot of the way the western/Russian doctrine differs in things like artillery and air support requests where in the west it's often the case that someone right on the front line can call for it*, whilst in Russia it requires higher authority.
Basically from what I understand the Russians are in a bad place to maintain artillery barrages even if the Ukrainians only had light weapons, as they started out without enough of a supply train (in the area) to keep it up, and the Ukrainians seem to have been paying special attention to that supply chain.
The cynic in me suspects part of the reason they've been doing local "cease fires" the last few days is it gives them a few hours at least in which to move supplies up to the artillery, and for them to get ready for the next heavy barrage.
Also iirc Kiev was rebuilt after WW2 specifically to act as a fort/slow down invasions, with very large numbers of bunkers/reinforced hold outs which is very different to the sorts of areas the Russians have flattened in Chechnya and Syria, they might be able do massive damage and kill vast numbers of civilians who are caught out in the open, but potentially still have a lot of armed defenders left operating (and those would be armed defenders who have had access to enough anti tank weapons to take out armoured vehicles in the open, let alone in conditions that were designed to hostile to invading armour).
*They're trained to do so, and trusted to know where and when it's needed, and the risks if they're calling for it to be near them.
