head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Optimization · Practiced Mastery
A study-level combat flight sim where mastering each aircraft's real systems is the price of entry.

Optimization · Practiced Mastery
Planning a raid in advance, then executing it where one mistake kills.
DCS World leans Optimization (Practiced Mastery); Tom Clancy's Rainbow Six leans Optimization (Practiced Mastery).
DCS World leans a little harder on execution, though the gap is small.
DCS World
Precise stick-and-throttle handling and BFM have a high ceiling.
Tom Clancy's Rainbow Six
One bullet kills, so entries demand clean aim
DCS World leans a little harder on reads, though the gap is small.
DCS World
Multiplayer dogfights against humans reward genuine prediction.
Tom Clancy's Rainbow Six
Multiplayer raids add human counterplay
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
DCS World
Sensor fog of war and unseen contacts hide information.
Tom Clancy's Rainbow Six
Terrorist placements are unknown until doors open
DCS World leans a little harder on optimization, though the gap is small.
DCS World
Full-fidelity avionics, weapons and tactics are a vast learnable system.
Tom Clancy's Rainbow Six
The pre-mission planning phase is the real game
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.