How many trains should I have

[doglol99]

I am transitioning my base from normal stations to ltn stations and I want to know how many trains I should have. Do I need to add a new train for every requester station or will less work without any issues

[ssilk]

If there is no trains waiting in the depot(s), you have obviously too less trains.
And the other way: if your depot is too full you have too much trains.

The optimum is, when at least one train is waiting at each depot.