Great considerations. The only thing I would add is that imho the Russian plan around Svatove of the last month was much more important than what is assumed and actually quite well thought out.

In my opinion it wasn’t a simple diversionary action: they probably really expected to reach the watershed between Zherebets and Oskil and in fact that area was perhaps the most suitable along the wider sector, topographically. If they had succeeded in reaching the heights and then managed to entrench, they could have started a second push from a very favorable territory in order to reach Borova. Moreover it was probably the area with the lowest density of Ukrainian forces from Kupyansk to Kreminna.

The Russians did reconnaissance in force with Storm Z units, shelled the area for a month in an extremely sustained manner according to Ukrainian accounts, and then attacked by employing elements of every maneuver unit of both the 4th Tank Division and the 2nd Army. Which were concentrated in a front of just 15/20 km, manned by a couple of (not particularly famed) Ukrainian brigades. It was a classic Soviet-style attack - recon in force, artillery barrages considerably outfiring the enemy, 3:1 ratio of attackers to defenders, which they most likely achieved in the initial phase of the push. The risk the Ukrainians faced was significant and they definitely suffered from Russian artillery superiority. Thanks to the deployment of reserves (the extent of which remains to be clarified) as well as their own artillery, the Ukrainians were able to contain it well, with the Russians stuck down the valley. It has been a poorly “mediatized” offensive - very few videos from either side, not that much equipment deployed (they are mainly forested and hilly areas, though tanks and BMPs were still reported to be employed): it was mostly a battle of artillery and infantry.

Having realized that the possibility of breakthrough in that area had faded, they are now getting more aggressive around Kupyansk (and in Novoselivske) by employing fresh formations. The Ukrainians are holding out very well luckily, but surely these events are still an headache for them. At the moment, however, I remain of the opinion that the Ukrainian choice not to abandon the eastern bank of the Oskil was correct.

Anyway… As far as Kupyansk is concerned, it has been like 3 times a week since March that the Russian bots have been saying that they had advanced 3 km in one day in that sector, if one is to believe them, he would think they reached Poltava by now. :D