I have heard that explanation before, but it doesn't make sense. Why not just "sell" the land to JS and then he could give it back when they return. I don't see why marriage had to be performed.
A man could leave to go 'back East' and come back to his house. Paying his taxes held it legally for him. In some cases he might have found squatters had moved in. Then he would need help to get them out.
But a legal wife could 'hold down the fort' when her man was away. She could also own the property if she had a male heir to inherit the property!
Women could not own property by themselves unless it was willed to them and or they had a male heir to hold it for.
The absent mens' property did not need 'protecting' except their personal property (their wives) from JS!
Considering that the church (Joe) was selling and giving people plots of land. And if they left the church they forfeited their property and left empty handed.
JS: Brother Gullible, what a hot wife you have. The Lord has just revealed to me that He wants you to go far away on a mission.
BG: OK, whatever you and God want.
JS: You'll need your property protected while you're gone.
BG: OK, whatever you and God say.
JS: Yes, I'll make sure your property is maintained and family is cared for. I'll regularly dip in to your wife to make sure she gets maintained too. Gee, I hope God doesn't tell me to have her sealed to me. Don't worry, we'll give you enough money to get to England.
He was willing to take the licked cupcakes. The poor dears would not have hope of getting a good man since they were used goods. How good of JS to stoop down to taking them in.
None of the "marriages" were legal in any sense, so none of the legal protections offered by marriage would have applied. AND, there's nothing he had to offer otherwise that would have performed that function, like, at all.
Doggone that Joe Smith was an altruistic man. To guard a traveling man's wife to the point of intimacy? That's going above and beyond the call. Not only that, Joseph would take care of the man's teenage daughters as well. I'm surprised the sheep didn't bolt in fear.