19 combat orders = ???

Do you get +2 to every skill, or +1?

Using 19 CO should theoretically give you 20 CO, which is a +2 to all skills. Basically, does CO affect itself?

No.

Combat Orders
Description Temporarily increase the skill levels of all party members. Only skills from the final job advancement can be increased beyond the mastery level.
Does not affect the level of beginner skills and Combat Orders.

Do you get +2 to every skill, or +1?

Using 19 CO should theoretically give you 20 CO, which is a +2 to all skills. Basically, does CO affect itself?

You just blew my mind.