A simple file checksum on the RAWs only tells you whether the files are byte-for-byte identical; metadata changes will make the checksums differ even if the sensor data is unchanged.

A better method is to extract only the raw pixel data and compare that. One community-tested approach is to use dcraw -D on each file, which outputs the non-interpolated sensor data as a simple grayscale PGM file. Then compare those outputs with a binary compare tool (cmp) or checksums. If the extracted pixel-data files match, the sensor data matches.

Another practical check is to strip metadata from copies of the RAW files with a tool like ExifTool and then compare checksums again. If the checksums match after removing tags, the difference was metadata.

You can also compare visually by opening both files with identical RAW conversion settings in an editor, stacking them as layers, and using a Difference blend mode. A black result indicates identical rendered output, though this is less direct than comparing extracted raw data.

For safety, always work on copies of your RAW files.