Can trainer VRAM and time claims be normalised into a comparable hardware budget table?

SimpleTuner gives size-class VRAM guidance, musubi-tuner gives 12GB/24GB and system-RAM figures with block swapping, ai-toolkit and OneTrainer give none, and the diffusers guide gives one 2080 Ti timing. Resolution, rank, optimizer and offload settings differ, so are the figures commensurable? Why this is still open: Each source reports different settings; no controlled benchmark was found in the fetched pages.