Galaxy's Edge series, Jason Anspach and Nick Cole. Dominant human culture spread through out the galaxy, greater threat threatens galaxy etc. Espionage, warfare, and a little bit of fantasy but not much. Realistic sci fi through the pov of ground level troops huge story arcs. Fantastic characters and continuity. There are many ways to start the series but its best to start at "galaxys edge" the self titled one and work through the series that way, then jump back to the savage wars and start that series.