Now is the time to let my inner geek out. 
So, I don’t have the sources now, but it’s pretty much accepted that the earliest deities to show up in human societies are connected to the land, fertility and agriculture. As societies become more complex, the gods may acquire or shift to more specialized roles. Quite a few gods of war were also gods of either fertility or agriculture. This might indicate a sudden militarization of said societies (for example, to defend the land from invading forces or struggling for resources during droughts).
The mental image is that of a farmer lifted from the wheat field to the battle field. These men would certainly bring with them the gods they were accustomed to, and not without reason. Being gods of the land, they would help protect it.
Ninurta was a Summerian god of war and agriculture, Inanna was a Mesopotamian goddess of war and fertility, Perun was the head of the Slavic pantheon and had many domains including war and fertility. Mars himself, the Roman counterpart of Ares, was worshipped as a god of war and agriculture, and despite not having any archeological evidence that Ares was worshiped as a god of agriculture, it is not hard to believe he might have been once before shifting roles. His possible lost role of a fertility god might also explain his lasting association with Aphrodite in the collective imagination of the Greek (even though the two of them were not married), since she’s also a goddess of fertility.
This is all to say that an idyllic pastoral image of Ares with a crown of flowers, chilling in the field under the shade of a tree, petting a fluffly sheep, surrounded by a rowdy army of children while he lets out a hearty belly laughter is not impossible or weird at all. After all, every soldier was first a father and a farmer in early human societies. The War Ares is the man who fights because he either has everything on the line or because he has nothing else to lose. Either a John McClane or John Wick.
In the story I was writting where you play as Thanatos, Ares was planned to make a brief appearance, and the way I planned to portray him was exactly that, a dying god, because he had forgotten his roots, focused so much on war that he forgot what he was fighting for. By the way, the premise was that all gods would die one by one (and that’s why they are not around anymore) and Thanatos would be the last one telling their stories.