One – Hosea needs to prove to himself that he still ‘got it’. In his journal, Arthur mentions how he thought Hosea would not make it out of them mountains alive. And some of Hosea’s lines as well as (maybe) the title of the mission suggest Hosea has the need to prove to himself that even thought he’s old, he’s still capable of hunting and fighting.

Two – Hosea is basically preparing Arthur for a post-outlaw life. While Charles taught Arthur the basics, Hosea gives him detailed guidance on how to track and kill animals, from small, easily hunted but oh-so-fragile lil rabbits to big’ole mean bears. He tells Arthur to go and hunt rabbits for dinner, only to decline any meat afterwards, as if he just wanted to make sure Arthur could hunt even small animals for quality pelt and meat. He makes a point on how Arthur in the past used a shotgun to hunt rabbits which literally decimated the poor animal. This serves as a clever way to tell the player that it does indeed matter what kind of weapon you use when you hunt animals. It also tells us that hunting has not been Arthur’s job nor responsibility prior to the events of RDR2.

For me, it felt like Hosea wanted to make sure Arthur could provide for himself after their time as outlaws had inevitably come to its end. He’s one of the few that has insight enough to realize they can’t keep living like they do. At one point, I think at Clemets Point, he specifically says he thinks they might be able to outrun/escape the law one more time or two. But then…

He will also tell Arthur at Clemets Point it’s time to start thinking. Several of his comments in chapter 2 and 3 is him hinting at how their lives as outlaws will come to an end soon. I think maybe Hosea wanted to make sure Arthur knew how to hunt for meat and for pelts to use in crafts or sell for money as he knows Arthur would have trouble settling down in society and likely would want to retreat to a quiet, rural life when the van der Linde gang is no more.

Or, simply…

Three – Hosea, knowing their lives as an outlaw (and likely his own life) is coming to an end, just wants to spend some quality time with Arthur, whom he thinks of as his son, just the two of them, while things are quiet. Before all hell breaks loose again and they have to flee – again.