Sunflower, I think you're right about empathy, sorrow and grief for loss being part of the oldest tales. Look at the 'Epic of Gilgamesh'. And for that matter, the 'Táin'. When I do my yearly gig as storyteller at the Gumeracha Mediaeval Fair, I always save the 'Fight at the Ford' from the 'Táin' to tell around the fire in the evening, to the Viking Society guys who have been doing fighting displays during the day. I count it a bad year when I can't make them cry. That part of the tale is where the hero and his best friend since boyhood/coweth companion/soulmate find themselves as champions on opposite sides in a particularly bloody and vicious war.
Up to that point the violence has been treated fairly lightly, in a sort of braggadocio-and-severed-heads-swinging-from-chariots way. Then you get the two young men confronting one another, each trying to talk the other out of it (but one has been tricked into giving his sacred oath to fight, the other is defending his helpless kindred just the other side of the border). They fight three days of formal setpiece duels at the ford, with no resolution. One has food, which he shares with his mate, the other has access to a healer, which he likewise shares. 'Their horses passed the nights in the same field, and their charioteers by the same fire'. Just to add to the tragedy, their two charioteers are brothers.
On the fourth day, they get serious. One is killed, and the one who killed him is completely shattered. His lament over his dead friend, the bit that starts: 'It was all play, all sport, until Ferdiad came to the ford' is one of the finest pieces of Irish epic poetry. But my point is that this incident is all the more poignant because for most of the epic the protagonists just man up and get on with it, because that's what you do when you are in an epic. There are moments of tenderness, some of them in Cuchullain's courtship of Emer, or 'The Tale of the Death of Cuchullain's One Son'; some in 'Deirdre of the Sorrows', which is one of the prequel tales to the Táin, but mostly these are subsumed in the action.
And I think that at present much of the open mourning and emotional debriefing of SSSS has been similarly been subsumed in the action. I think we will see some of it eventually, but not yet, because it would be unwise of the characters to do that stuff in the midst of fighting/running for their lives. Though I would be unsurprised if some of it came out between Mikkel and Sigrun, talking by the fire through the long dark nights...
There is a final bit to 'The Fight at the Ford', where the hero is collapsed mourning and bleeding over his dead friend, and his charioteer comes and shakes him and tells him to get moving if he wants to live, because 'The men of Ireland are coming for you now, and now that Ferdiad has been slain, it is no longer of single combat that they are thinking......'. Always the practicalities, just when one is settling down for a nice long angsty brood!