I think most of the members of revolutionary army including dragon and other important ones , must have left for that important meeting with other companies of revolutionary army, giving Blackbeard an almost empty base
I believe Blackbeard won the battle. After Blackbeard won, CP0 went to Baltigo I believe and all of Baltigo got destroyed. I believe the important members of the Revolutionary Army survived but got split up and I also believe when CP0 came, Blackbeard already fled. I think most of his crew got badly injured.
There's no war. Blackbeard arrived and destroyed Baltigo. Dragon told Koala to call the commanders to gather in a place for an important meeting so the revolutionary army might have abandon Baltigo before Blackbeard pirates arrived.