Assuming I understand your question, no the implementation can be different as long as the consensus rules are followed. The only thing is that if you have lots of competing implementations, I believe you can get accidental/unwanted forks in the chain.
Discussion
Yup which is why knots is pretty much perfect for this use case since it is basically core and has been maintained right alongside it for the majority of core’s existence yet nostr:npub1qny3tkh0acurzla8x3zy4nhrjz5zd8l9sy9jys09umwng00manysew95gx is frustrated by knots for some reason… so I was wondering if he’d consider using something like btcd… but I don’t think he would for the reasons you mentioned.