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

Execution · Practiced Mastery
A team shooter where aim and positioning against human opponents controls the map.

Execution · Competitive PvP
Simulation-styled WWE entry praised for its showcase mode and refined reversal-based combat.
Splatoon 2 leans Execution (Practiced Mastery); WWE 2K19 leans Execution (Competitive PvP).
Splatoon 2 leans a little harder on execution, though the gap is small.
Splatoon 2
aim and movement decide ink battles
WWE 2K19
Reversal timing windows and combo execution
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Splatoon 2
predicting human opponent positioning
WWE 2K19
Human versus matches hinge on counter prediction
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Splatoon 2
weapon and map rotation randomness
WWE 2K19
Slight randomness in pin kick-outs and AI
Splatoon 2 leans a little harder on optimization, though the gap is small.
Splatoon 2
loadout and turf strategy solvable
WWE 2K19
Payback systems, move-set knowledge and MyPlayer builds
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.