It is Jingo, but it isn't General Tacticus - simply Sybil's thoughts about war and Vimes, something we rarely see (i.e. Sybil's thoughts about anything).
*But you’d go another eye, right? And now you had solid proof that you were a hard man especially if you got one of those scars that run across the eye and down the cheek. Get a black eye-patch, and you would never have to wait to be served at a bar never again.
"It is a long-cherished tradition among a certain type of military thinker that huge casualties are the main thing. If they are on the other side then this is a valuable bonus."