Zwift racing depends on everyone choosing the correct category, which never happens 100% of the time. There will always be sandbaggers racing in lower categories so they have a better chance of getting a “win”. This is where Zwiftpower comes in and filters out all the sandbaggers so you’re compared to other true category racers.
I did the stage 1 race yesterday in cat C, my first cat C race after getting a smart trainer and my power being correct for the first time. My FTP is now 264 and I weight 90kg, or 2.9 wkg, so you would expect that I finish close to the front if I’m experienced and know how to use tactics in Zwift races. I finished 40th on the Zwift leaderboard, but Zwiftpower has me at 21st place. The 1st place winner on the zwift leaderboard was pushing 3.3 wkg, 2nd place 3.4, 3rd 3.95 - they should all be in the B cat race.
You should sign up for cat C and see what happens. Zwift racing starts very fast so be ready to come out of the starting pens at full gas and then try to hang on to whatever group you find yourself with whether that be the front group, middle of the pack, or the back. Get in the draft and hang on as long as you can. If there are hills be ready to surge up them, use power ups at the right time to be strategic, and save something for the final sprint.
Good luck, it’s great fun and I hope you enjoy it!