head to head
Supreme Commander 2 asks more than Guild Wars 2, and the gap is reads.

Optimization · Practiced Mastery
Active dodge-heavy combat with a deep build system, tested against both scripted content and human opponents.

Optimization · Grand Arena
Large-scale RTS testing economic optimization, multitask speed and prediction of human build choices.
Guild Wars 2 leans Optimization (Practiced Mastery); Supreme Commander 2 leans Optimization (Grand Arena).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Guild Wars 2
Dodge timing and active combat define moment-to-moment play
Supreme Commander 2
Macro APM across huge armies separates skirmish winners
Supreme Commander 2 leans clearly harder on reads.
Guild Wars 2
WvW and structured PvP feature real adaptive opponents
Supreme Commander 2
Multiplayer rewards scouting and predicting a human's tech switches
Guild Wars 2 leans a little harder on variance, though the gap is small.
Guild Wars 2
Loot RNG is present but secondary to skill expression
Supreme Commander 2
Open maps leave little hidden beyond fog of war
Supreme Commander 2 leans a little harder on optimization, though the gap is small.
Guild Wars 2
Build crafting and rotation theory-crafting reward deep analysis
Supreme Commander 2
Economy ratios, build orders and research routing are deeply 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.