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

Optimization · Mind & Math
A sloppy RTS still testing build orders and economy ahead of micro.

Optimization · Pure Optimization
Instanced online RPG where deck-like eight-skill builds decide battles before they begin.
Empire Earth III leans Optimization (Mind & Math); Guild Wars 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.
Empire Earth III
Macro speed matters though far less than in tighter RTS peers
Guild Wars
Interrupt timing and kiting in skirmishes
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Empire Earth III
Human opponents' timing attacks must be scouted and predicted
Guild Wars
GvG and arena metagame against adapting humans
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Empire Earth III
Map starts and AI behaviour hold mild unknowns
Guild Wars
Modest drop and spawn randomness
Guild Wars leans a little harder on optimization, though the gap is small.
Empire Earth III
Epoch timing and economy builds dominate outcomes
Guild Wars
Eight-skill build construction is the game's soul
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.