I learned a couple interesting facts messing about on the later levels of Breakdown.
1. Lost heroes have a chance to reappear at any later level. I lost Amelia Crasman (one of the best heroes I've come across so far) literally ten minutes after unlocking her and was so pissed off words can't even describe it. A few levels later I found her in an enclave (along with Joel who I had also lost) and was able to recruit her again. I knew you could find survivors you had left off the RV later on, the fact that dead ones can also respawn is pretty cool.
2. If you need to bump up your community size fast and have 100 influence to spare you can have Lily search for other survivors which after a few minutes will put you into contact with a group you can immediately recruit without having to grind through a series of trust missions for their enclave. This is especially useful if you want to move directly from the RV into a larger home site (like Snyders Trucking or MacReadys farm) right at the start of a new level.
The last Breakdown achievement I'm chasing is going to drive me insane. The Rescuer achievement requires that you unlock every possible hero and the last one I need is "the Killer" which you need to do a mercy shot to unlock. I've been lingering on level six forever trying to get this to unlock and I just cannot get it. I haven't built a medical facility, I've long been out of medical supplies and I even dragged Doc out into the wilderness and let him get mauled so I have no medical personnel. I have almost my whole community sick, with many hovering at "Gravely Ill" but this mission NEVER pops. I've even been recruiting new enclaves, purposefully getting them mauled to near death and exposing them to bloater gas on their way back home. I know I've said this before but I'll say it again, I hate luck based achievements.