How many skills is too many?

[LalaRu]

Use on every character 3 slots for one class from each disciple (except the disciple of the current class)
Then fill up the other slots on DoW jobs with the other DoW jobs, on DoM jobs with other DoM jobs and so on.
Now you can switch to every class with just switching first to a class of the same disciple.

Quite smart, will use just one hotbar instead of three
Just a little work to set it not shared, and fill it correctly for each job. Good hint.