CX and gravel racers who size like a road-race bike. If you want Future Shock and mounts, Diverge is the sibling.
The light gravel/CX race bike: lower and snappier than Diverge, with less adventure hardware. It feels like a Tarmac that grew tire clearance.
Gravel riders. Orca if you want road race; Occam if you want MTB trail.
Orbea gravel: stable, mounts, and a calmer chart than Orca. It wants mixed surfaces and longer days.
Racers and fit club riders who want a low stack without full aero integration. If the Aeroad cockpit feels like too much, this is the sibling.
Canyon's lightweight race bike: snappy, precise, and less of a wind-cheater than the Aeroad. It rewards a committed position and calm hands in corners rather than a slammed aero tuck.
Gravel riders who want Giant's drop-bar all-road, not a TCR with knobbies.
Giant's gravel bike: stable, mounts, and a position between Defy and a race gravel whip. The X variants add more suspension/travel attitude.