Since they are a powered and non-powered set you don't have to run in a lashup but for all the lighting etc to be more as intended then run as a lash up (TR).
In my son's room he has the ABA set that has a 2nd powered unit and we put them in a lash up to run correctly. You could also program all the engines with the same ID as well, but again some of the lighting etc. might not be the way it should be.
Run as a MU (Multiple unit or lash up), it isn't that hard after getting it setup and it engines will keep the settings.
Jim