There is an difference between creating lots and lots of text and sell this as "groupintercations" and creating really relationships and D:OS created at least a real relationship between the two source hunters. Who were the focus of the story and actually got some personality, even if this was over the mechanics.
No, that's wrong. D:OS created an ARTIFICIAL relationship between the two source hunters. It was not a relationship which felt real, mostly because it was constant throughout the entire game.
The Source Hunters really had two types of interactions: The pre-scripted bantering which happened back and forth about a world event, and the dialogue where the player and the AI personalities could pick a choice.
In my case, the first time through, I picked AI personalities which were opposing, and so O experienced seeing the SH's cleverly banter in a friendly manner in-between rabid arguing about what to do. The final disconnect was at the end, where after a game of the pre-scripted friendly clever banter, I was told that my source hunters spent the rest of their lives in a hate-filled battle to the death between them.
It was not a real relationship because there was no change at all in it. It was static from start to finish.