head to head
WWE 2K15 asks more than Nintendo Switch Sports, and the gap is optimization.

Execution · Competitive PvP
Motion-controlled party sports where reading your opponent's swing matters.

Execution · Competitive PvP
Reversal timing and pacing against an opponent baiting your counters.
Nintendo Switch Sports leans Execution (Competitive PvP); WWE 2K15 leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Nintendo Switch Sports
Motion swing timing and placement accuracy
WWE 2K15
Reversal timing windows decide most exchanges
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Nintendo Switch Sports
Human opponents bait and counter in volleyball and chambara
WWE 2K15
Human opponents bait reversals and vary move timing
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Nintendo Switch Sports
Light physics jitter and matchmaking spread
WWE 2K15
Chain-wrestling rock-paper-scissors minigames add randomness
WWE 2K15 leans clearly harder on optimization.
Nintendo Switch Sports
Simple per-sport strategy ceilings
WWE 2K15
Move sets, stamina and match pacing are learnable systems
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.