How does bitrot protection actually work?

StephenB wrote:
...I do have defrag, balance, scrubs, and disk checks scheduled in the maintenance schedule (each is run once every three months on each volume).

Could you advise the optimum order for the
1. Disk Defragmentation
2. Disk Balance (Not certain what this means - comment please?)
3. Data Scrubbing (Incorrectly described as Disk Scrubbing in the forums, which is something else entirely)
4. Disk Checks (CHKDSK ?)
if you do these end to end (or a day apart, say).
OR
do you spread them randomly/evenly through your 3 month period?