Sorry.
You will NOT get the Timecode to transfer using a second small camcorder as a recorder.
You won’t get the Timecode “breaks” to transfer, as the recorder camera will substitute continuous new TC of its own.
The QUALITY will not “lose a generation” so your audio and video will be perfectly duplicated, but the camcorder that is in the “record” mode will ignore the TC on the master tape.
The only way to make copy WITH matching TC is to use a recording DECK with a feature that allows setting for “external TC.”
A camcorder does not have that feature.
BUT, since all you want is a “back-up” just in case something happens to the camera originals, the TC should not matter… unless you’ve already done an “offline” with the original and you DO lose the masters.