I've always verified the checksums of files transmitted via netcat and occasionally I have had different checksums. It's rare, and only on gigabyte+ files, but it has happened.
You should just use rsync - its been the best tool for transfering files between UNIXoids for the last 15-20 years for me and comes preinstalled with most distros (even macOS). It will take care of transferring only the required parts, and if you supply -c (slow!) it will even perform checksumming on both ends to assert files were correctly transferred and are bit-identical.
