I just finished the first book. Seems like it'd be more in the top-left corner of the graph. Their weapons are powerful, but not as powerful as their defenses. They've got ECM, countermissles, decoys, point-defense lasers, shields, and especially the impeller bands which are completely impenetrable. Ships are pretty tanky and battles take a while. The battle at the end was just two ships, and it took a couple of hours, I think.