When i was re-listening to chapter 9 part 1, after listening to the balance of power, i picked up on the conversation between angel,datu and riley. (1min+)
datu: Whys it so important we know where they are?just to avoid it?
angel: Your not thinking in the big picture
riley: What?
Angel: If theyre all in one place, at least a nice chunk of them, its the only place you have to hit, we'd never be able to pick them off one at a time, then again we dont know how many theyre are, some of the many reasons we need to find out
Datu: So were going to count them?!

For some reason angel saying "your not thinking of the big picture" hits me, Then when he mentions knowing if a large amount of Z's are in the same place that would be the only place to hint, "We'd never be able to pick them off one at a time".

Those two phrases for some reason made me think of perhaps inks appearances, he is always watching (possibly counting) the survivors, never directly interfering until he enters both of the towers, maybe ink is tracking the remaining survivors, counting them,keeping watch and waiting until they are in a big chunk ready for a single strike (Boulder Colorado anyone?).
Then after the fall of boulder/Irwin, The cast all relocate to the colony, along with any remaining colonists/Irwin soldiers.

i know you guys will just tell me that theyre tracking the zombies to find the nest but what if it was the other way round?
we all know KC loves putting small details that are pointless at the time, then when we go back after a few chapters our minds get blown

OHH and also i forgot chapter 9 was called The road to living death....

Love to know what you guys think!