Avira > rema doesn’t allow “war stories”, he mentions specifically Josephus
? my rema says: בשיחות חולין וספורי מלחמות
But overall I agree that the idea here is of spending time productively, as, for example, the next seif allows working with an astrolabe. Also mentioned sifrei chochmot. Idea of pareve entertainment for relaxation is not there. But the question remains whether feeble modern minds require that. So, maybe no need to recommend watching sports l’hathila but for those who are used to that and not abusing it, maybe it is Ok? similar to previous psak on smoking.