From my experience you can have the same program (Tane or 2019) on several computers.
If you download content from the DLS it will only work in one at the same time, if you use the other you will receive an error and no download.
It is best to only use one program at a time, once closed it can be used on another computer.
I use a computer as a database with a lot of content and another computer with little content to play the simulator, for better performance.