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

Optimization · Practiced Mastery
Galaxy-spanning space sim about flight and trade.

Optimization · Practiced Mastery
Planning squad approaches to scripted missions where one mistake kills.
Elite Dangerous leans Optimization (Practiced Mastery); Hidden & Dangerous 2 leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Elite Dangerous
Flight controls, docking, combat aim
Hidden & Dangerous 2
Deliberate aim and stealth movement punish sloppy hands
Elite Dangerous leans a little harder on reads, though the gap is small.
Elite Dangerous
Light PvP reads, mostly PvE
Hidden & Dangerous 2
German AI follows patrol scripts, not adapting to you
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Elite Dangerous
Procedural galaxy, mission variance
Hidden & Dangerous 2
Patrol routes and enemy positions are unknown first attempt
Elite Dangerous leans a little harder on optimization, though the gap is small.
Elite Dangerous
Ship build, trade routes, engineering grind
Hidden & Dangerous 2
Squad planning, loadouts and approach routing decide missions
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.