what's the artillery ratio between the two sides again?

At least 5 to 1, which is also around the same ratio we see in the casualty numbers. This is completely unsurprising as artillery has always been responsible for most of the casualties in a war of this kind. And on top of that Russia is using a huge amount of glide bombs and cruise/ballistic missiles that Ukraine doesn't even have. So they can break any fortified position and target logistics and C&C nodes pretty much at will. Hence why the "attacker always suffers more casualties than the defender" cliché does not apply here.

Not to mention that it's not even that cut and dry who is attacking and who is defending. The Ukrainians take a lot of losses in counter-attacks because they are very unwilling to give up ground (the Kiev regime is very dependent on optics for whenever it goes begging for money and weapons, it has to appear like it's holding on and that it still has a chance to regain lost territories) and they will often send wave after wave of men trying to regain lost positions even after they have been taken and the Russians have entrenched themselves there.

Speaking of cannons