League Of Augsburg - Fighting Talk

I have a copy of the War of Three Kings rules and am currently building up armies for the Williamite period in Ireland using the Pendraken 10 mm League of Augsburg range. Pendraken produce artillery pieces listed for 3, 6, 9, and 12 pound guns. My question is how would these fit into the rule definitions of small, light, field and battery. Do I simply allocate them as 3 to small etc. or was it not, historically, as straightforward as this? Any help or advice would be much appreciated.

Grahame​

for simplicity sake I would go with exactly your summary/interpretation

cheers

B