I think it might be more that Russia cannot protect its artillery well enough to use it in a lot of situations Russia really needs artillery support, so occasionally Russia will commit green artillery crews to suicidal fire missions that are absolutely necessary, they fulfill their mission and then are eliminated by Ukrainian drones or counter battery fire.

I think this has been going on so long that this plan doesn’t even work anymore for various reasons, in particular the range is probably too short on the towed howitizers Russia can afford to throw in handfuls at Ukraine to shift the momentum at the front.

This is just speculation, but it is the best fit for the limited information we have that I can think of.

Also, yeah I would take these numbers with a bucket of salt, I have no idea how or if they are corroborated.