The Rebels didn't know a lot about Warfare at first. Hell, the entire Republic didn't really know much about Warfare, so were very happy to have a bunch of cloners breed and train expendables for war. Bail Organa was just a Diplomat from a peaceful planet.
The Rebels were able to band resources together in order to build all those X-Wings, but by and large they didn't have a proper Military until ESB when they started to amass their forces near Sullust before the attack on the second Death Star in RotJ.
At most, they were ill equipped terrorists that got lucky.
Knowledge Warfare would only come in handy for the Empire or Imperial forces that defected to the Rebellion, which wasn't many. The Rebels were very happy to use spies, smugglers and anyone else who was willing to work for them, at a price. Rebels were more hit and run than warfare, so I don't think warfare really describes Rebels at all.
Knowledge Galactic Civil War easily covers the political and freedom fighting angles of the Rebellion.