2nd trip: Fukuoka and Sapporo?

Hello, I’m currently planning my second trip to Japan. The first time we did the typical route and visited Hakone, Kyoto, Uji, Osaka, Nara, Hiroshima, and Tokyo. This time around we wanted to do Osaka (just a night or two), Fukuoka (4 nights?), Sapporo (4-5 nights?), Tokyo (6-7 nights?), and then head to Seoul before returning home.

Would you agree with visiting these cities or is our time better spent elsewhere? We would take the Shinkansen from Osaka to Fukuoka and then fly to Sapporo and fly back to Tokyo.

Any advice is appreciated, thanks!