head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Optimization · Pure Optimization
A streamlined click-along action RPG famous for its seamless world.

Optimization · Pure Optimization
A creative vocabulary puzzle about conjuring the right object for each prompt.
Dungeon Siege leans Optimization (Pure Optimization); Scribblenauts Unmasked: A DC Comics Adventure leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Dungeon Siege
Combat mostly resolves itself
Scribblenauts Unmasked: A DC Comics Adventure
Typing words is the only physical act
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Dungeon Siege
Mobs charge on simple scripts
Scribblenauts Unmasked: A DC Comics Adventure
Puzzles are static prompts, no adversary
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Dungeon Siege
Loot drops vary modestly
Scribblenauts Unmasked: A DC Comics Adventure
Objectives are visible; little stays hidden
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Dungeon Siege
Party builds and pack-mule logistics are the game
Scribblenauts Unmasked: A DC Comics Adventure
Finding clever word-object solutions is the entire test
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.