Given the way the remains are lying, I'd say they were fast asleep when death occurred.

This means it could have very well been one killer.

The spears themselves may have belonged to the victims.

That suggests they may have been guards.

Guards certainly do make a lot of enemies. They are also targeted simply for being figures of authority.

Perhaps these guards were off duty, enjoying a meal. The overturned wine bottle suggests they may have drunk too much and it made them sleepy.

The killer was opportunistic.

The killer simply crept over, took the first spear, and drilled it right through the head into the ground where the victim slept. He/she then did the same again to the second victim.

Also, given the natural sleeping pose of the victims, and the lack of rusting/decaying armor, I would say the victims were either completely naked, or wearing very little at the time of death.

The bodies would have been disturbed if the killer removed any armor.

As for motivation, the natural surroundings, far removed from town or city suggest the killer did not gain access to anything of importance by killing them. The food has been left, and again, there is no residual evidence of armor and little to suggest any possessions at all.

So I return to the wine. The blanket. It seems to have been a planned meal, not impromptu. The wine and cheese suggests celebration of some kind.

I am hesitant to suggest a proposal of marriage, given the sleeping couple were not embraced, but perhaps a birthday, a promotion, any other occasion where the exchange of gifts are not unexpected.

Though with little hard evidence of this I can only conclude that this was merely an opportunistic attack by at least one killer. The murder weapons may have belonged to the victims who were asleep at the time of death.