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
Wasteland open-worlder upgrading one car to conquer scripted scrap territories.

Optimization · Practiced Mastery
The sequel adds minion mounts and an evil empire to corral with your goblin hordes.
Mad Max leans Optimization (Practiced Mastery); Overlord II 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.
Mad Max
Car combat and counter-brawling timing
Overlord II
Minion sweeps plus mounts need moderate control
Overlord II leans a little harder on reads, though the gap is small.
Mad Max
War boys follow fixed AI
Overlord II
Scripted empire enemies
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Mad Max
Open world is static once scouted
Overlord II
Deterministic encounters
Overlord II leans a little harder on optimization, though the gap is small.
Mad Max
Magnum Opus upgrades and stronghold routing
Overlord II
Minion management and domination choices are solvable
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.