With size 10 I couldn’t seem to find any military outposts, but labs still appeared far from cities. Is there a maximum city size/spacing option so I can have larger cities, but still be able to get everything to appear?
Hmm come to think of it, all I have ever seen are small town like areas. Is it possible for the game to spawn big cities, like a Boston or Pittsburgh type of city? With lots of densely packed, close together buildings in the center, with suburbs on the outskirts? Skyscraper or office type buildings?
try city size with max settings & see what happens! 
I had city size 12 with spacing 7 everything could spawn it is not your city size that matters it is city spacing
not organized at all and not skyscrapers (the tallest being 4 stories) but BIG cities can spawn in the same world as TINY ones (I had spawned next to a city called Bucksport which was very large(every city I’ve found since than was smaller) but there was also China which was a 3x3 with 5 houses with an above average amount of toxic waste dumps near it with the only military facility near china being a nuclear launch silo and the city of Leput which is the same as china but with a train station with a track that goes only 100 feet and is wider across than a bus is long