This was an interesting article about the so-called tooth-to-tail ratio over the millennia. The "tooth" is the troops that do the actual fighting while the "tail" is the people who make sure the teeth get all they need - delivering ammunition and fuel, keeping the vehicles combat-ready, etc. Over the years the ratio of tooth to tail has kept shrinking. The Roman legions were pretty much all tooth, lancers in the 15th century had an 8:1 ratio of tooth to tail. That ratio had reversed by the early 21st century.
Deveraux argues that the teeth will continue to become smaller and the tail larger as technology becomes more complex and more capable. What do you think? Have you thought about this when creating sci-fi universes?