You've already found your answer and moved on, but just to explain running a highly resource intensive game like TS3 through Parallels is theoretically possible, and mods such as ours from NRaas don't care about the operating system as they run in the game environment only, but the game experience would not be expected to be very good because Parallels makes one operating system run on top of the other. And, currently, TS3 for Mac is crippled in that it can only address 2 GB of RAM no matter how it is installed. A better way to run TS3 on Mac hardware is to Bootcamp Windows onto the system and run the TS3 for Windows version instead, provided one has enough drive space and the patience to manage two operating systems. There is a new version of TS3 for Mac due out later this year from EA that (we hope) will fix the Catalina OS and resource limitation issues, but no one really has any kind of ETA on that one.
