In The Iliad 6.12–19, we find the following poignant passage about a fighter on behalf of the Trojans who falls by way of Diomedes:
Diomedes of the great war cry cut down Axylos,
Teuthras’ son, who had been a dweller in strong-founded Arisbe,
a man rich in substance and a friend of all humanity
since in his house by the wayside he entertained all comers.
Yet there was none of these now to stand before him and keep off
the sad destruction, and Diomedes stripped life from both of them,
Axylos and his henchman Kalesios, who was the driver
guiding his horses; so down to the underworld went both men.
The lesson I gather from this passage is as follows.
Hospitality is indeed a very important virtue, one which Homer emphasizes at great length in The Odyssey, and I sense an element of fond admiration of his description of Axylos as a “friend of all humanity” (φίλος δ᾽ ἦν ἀνθρώποισι). At the same time, the battlefield is not the household or the city.
In war, different virtues are needed, and a capable householder or host is not necessarily the better soldier. In war, what is needed are the virtues particular to soldiers: physical strength and endurance, a willingness to kill, facility with a weapon, strategic insight, and so on.
The best sort of man will always strive to have the virtues necessary for success in whatever circumstances he finds himself in—or else he’ll try to mind his business and stay in his proper place.