How long do I need from landing to reaching the train station in Zürich Airport when arriving from London?

I am arriving at the Zürich airport from London, scheduled to arrive at 6:20pm in the evening. I am wondering if anybody has an approximate idea of how long it normally takes to get to the train station in the airport once one has landed when coming from England with checked luggage. Depending on the time it takes I would have to decide between two options to get to my final destination: 1. a long distance train leaving around 9pm. 2. take a train from the airport to the central station at around 8pm, to catch a bus at central station at around 8:45pm (I read that the trains from the airport run about every 10 minutes and take 10 to 15 minutes to arrive at central station. Is that correct?)

The advantage of option 2 is that I would arrive 45 minutes earlier at my final destination, which doesn't sound like a lot when it's in then middle of the day, but when it's close to midnight it makes a bit of a difference for me. It would also be slightly cheaper.

I am wondering whether it may take me much longer to walk to the train station than another person that asked a similar question on here, because I'll arrive from London and not from Berlin? Furthermore, I am wondering how long it approximately takes to receive the luggage as this can vary greatly according to my experience.

Other information that may be important: - I am a EU citizen - London is just a layover (long connecting times. It's extremely unlikely that I would miss the flight) - The flight will be operated by British Airways

Thank you for your help! I really appreciate it.