They're not actually bringing these up to fight tanks. Their 100mm barrels are poor for that job this century. They're going to use these for indirect fire, because they're losing so many tubes to wear and counter battery fire.
Still indicative of the state of today's Russian army that they've resorted to this. I'm amazed by the Russophiles on this forum that are unphazed by these developments.
They will still be spotted several miles away.