I'll add a few of my own thoughts about the MC and the LI situation:
The MC was coasting/existing after the breakup of his marriage; it felt like it was almost 'Groundhog Day' in the sameness of the weekdays (and I'm guessing weekends).
Disasters can break some people and for others, they find purpose.
I think this disaster forced change on the MC. It woke him up from his daily grind of sameness and forced him to examine the world around him and he chose to start to live again (it truly was either that or just give up and die).
At first, he was isolated, having barely more than work acquaintance relationships with both Kallie and Laura, but the disaster and time spent together, depending on each other, brought the MC, Kallie and Laura all closer to each other.
Physical intimacy is a choice we make for the MC - and I was fine with the way that intimacy evolved with both Laura and Kallie. The MC recognizes that he needs to let the women know he is being intimate with both of them and is wrestling with the 'how' to do that without creating dangerous drama that the group cannot afford.
I don't think this makes him weak; I think this makes him human and less than perfect. He has two women that chose Him for intimacy after being emasculated in his marriage for some amount of time. This is a kind of affirmation that he did not have in the sameness of his old 'I'm just an ex' life.
He regularly has an internal dialogue trying to make sure he is not taking advantage of either Laura or Kallie (and I think that the f buddy status he has with Shelley helps in this). Both women are adults and less than perfect. He is a part of their affirmation that they are attractive and desirable, even without makeup and all the modern amenities that they would have had access to prior to the disaster.
The MC is responsible, invested in protecting and caring for both Laura and Kallie, and he is still the good guy whose conscience will not allow him to let Shelley just stay in the dorms - f buddy or not (even knowing she is out of her meds).
I absolutely agree with you about the range of benefits that each person in the group offers the others in the group, including:
* Others to talk with (like it is easier for Shelley to talk with Kallie than Laura)
* Maternal caring (Laura, even after her break, still wants to help protect Kallie from her fiancée)
* Mutual protection - literally guarding each other's backs
* Being reminded that they are not alone and can rely on others and benefit from a broader group skill set (early on, Kallie contributed by making fast food for the group - pre-Shelley - even though she felt that she was unable to offer the group much beyond that)
Success in this situation is - survived a move to a new location; a day where no one got injured or overly exposed to the caustic fog; found a relatively secure place to stay for the night.
The current location is hardly ideal from a food/comfort/extended stay perspective, but 4 sets of eyes offer improved protection and a better chance to notice something important versus the 'man alone' scenario.
Cheers!!