Games like SPEED: 8.X
Games like SPEED: 8.X include Total War: WARHAMMER II, Men of War: Assault Squad 2, WARNO, Wargame: Red Dragon, and Ultimate Epic Battle Simulator 2. We matched them by the tags players give SPEED: 8.X on Steam (Action, Simulation, RTS, Auto Battler, and Wargame): closest matches first, and among equally close ones the better-known games.

Total War: WARHAMMER II
Shared: RTS · Strategy · Action

Men of War: Assault Squad 2
Shared: RTS · Simulation · Action

WARNO
Shared: Wargame · RTS · Strategy

Wargame: Red Dragon
Shared: RTS · Strategy · Wargame

Ultimate Epic Battle Simulator 2
Shared: Simulation · Action · Strategy

Total War: WARHAMMER III
Shared: RTS · Strategy · Action

Totally Accurate Battle Simulator
Shared: Simulation · Strategy · Indie

Steel Division: Normandy 44
Shared: RTS · Simulation · Action

Steel Division 2
Shared: RTS · Strategy · Simulation

Mount & Blade II: Bannerlord
Shared: Strategy · Action · Simulation

Call to Arms
Shared: Action · RTS · Strategy

Kingdom Heroes 8
Shared: RTS · Strategy · Wargame

Broken Arrow
Shared: RTS · Wargame · Strategy

Total War: WARHAMMER
Shared: Simulation · Strategy · RTS

Door Kickers
Shared: Simulation · Action · Strategy

Bad North: Jotunn Edition
Shared: Wargame · RTS · Real Time Tactics

Total War: THREE KINGDOMS
Shared: Strategy · RTS · Action

Master of Command
Shared: Strategy · RTS · Wargame

Carrier Command 2
Shared: Simulation · RTS · Strategy

Mechabellum
Shared: Auto Battler · Wargame · Strategy

Wargame: Airland Battle
Shared: RTS · Strategy · Wargame

Creeper World 4
Shared: RTS · Wargame · Real Time Tactics

Ultimate Epic Battle Simulator
Shared: Simulation · Action · Strategy

Ultimate General: Gettysburg
Shared: Simulation · RTS · Strategy