Skirmishers

Battles when im overnumbered and they got cavalry, its hard to put units in formation until they arrive. Especially becose i have like 4-6 ranks. So i was thinking, if i would have skirmishers, i could just order them to hold out the enemy until my troops are in position, and start advancing.
Any tips hwo i could use as skirmishers? Someone hwo are though, but cheap. And possibly some javs.

You mean have a group run while you steady the ranks?

I use cheap cannon fodder British troops as my first line and tell them to charge while auxiliary stands behind and provides pila support.

yes thats what i mean. Thanx for the answers, i use auxilia i got to weaken enemy while i form my units in formation, and do a final and decive blow with my more elite Legionaries