So this is why they're using those old tanks as artillery (besides the ammunition shortages)

That only works for so long depending on how many artillery pieces Russia has in reserve / can move to the front. Of course, NATO can keep Ukraine topped up, so on balance I think Ukraine will come out ahead.

I was hoping the ratio was even higher. 1/4 would mean over 1000 artillery pieces and therefore personnel lost.

Seems off. How were these destroyed items identified. I can see the Ukraine allowing outside observers in but I just don’t see Russia allowing them in. Russia is too secretive and sketchy to be transparent.