Link a few DNG‘s that are problematic. How do you expose? Do you ettr? Do you under expose?
Regarding your resolve output. I can‘t speak for Prores, but it is well known that the Resolve h264 encoder is sub-par compared to other encoders.
If your delivery requires h264/5, then you are better off exporting a Prores master and then use adobe encoder to convert the prores to h264.
The 5d2 is more noisy than 5d3, the line skipping introduces a lot of artifacts, especially in body of water or foliage. Basically elements that have high frequency of details or changing details.
Over-sharpening, as long as you are working with mlv/DNG, you are the only one who can introduce this over-sharpening. Again, post some dng‘s.