I’m running exactly this setup, but without the cintiq. I use the PC for virtually everything and the Macbook for when/if I have to work away or present something to management.
The Macbook that I have (2014 model) does lag a bit using Solidworks and doesn’t handle Keyshot too well. A higher spec’d Macbook with a dock to keep peripherals plugged into and a larger dedicated screen to go with the Cintiq would be an easy and streamlined option.