I really enjoyed the Black Fleet Saga by Joshua Dalzelle.
The Expanse
The foundation series by Asimov has a lot of similarities to both of those sagas in tone and content.
Red rising is great sci-fi, but it's more enders game(although a little more hardcore action).
I'm going to let this rattle around, I feel like there's something else I'm not remembering right off the bat.
Oh I guess not quite the same, but when anyone asks for a recommendation in sci-fi, I always say "the mote in God's eye" by Jerry pournelle and Larry niven
Not as large a scale as those books, but a fascinating story told in a unique and scientific way.
Revelation Space series by Alastair Reynolds
I asked a similar question right after I finished The Expanse and the response I received was to read Revelation Space. Needless to say I wasn't disappointed!
I'm working on The Culture series by Ian Banks now.