When it comes to Metatrader, the main difference between the free and paid (S) version of Zorro is that you can only perform real trades with the paid version.

With asset() (see https://zorro-project.com/manual/en/asset.htm) you can call any asset you want and thus have multiple strategies in a single script. Attach the Zorro EA to 1 single chart (again, read the MT doc in the manual for details).

I'm not affiliated with Zorro, but I would suggest to demo trade first and then invest in a Zorro S license once you have good results.