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

Execution · Competitive PvP
Classic fighting execution and human prediction atop a famously unbalanced roster.

Execution · Competitive PvP
The Wii U Smash that restored competitive pace and a huge roster of labbable kill confirms.
Mortal Kombat Trilogy leans Execution (Competitive PvP); Super Smash Bros. for Wii U 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.
Mortal Kombat Trilogy
Dial-a-combo inputs and run-meter pressure demand fast hands
Super Smash Bros. for Wii U
Perfect pivots and precise aerial spacing reward sharp hands.
Super Smash Bros. for Wii U leans a little harder on reads, though the gap is small.
Mortal Kombat Trilogy
Human opponents must be baited into unsafe moves
Super Smash Bros. for Wii U
Ledge-trap and landing-trap guessing against humans never converges.
Super Smash Bros. for Wii U leans a little harder on variance, though the gap is small.
Mortal Kombat Trilogy
Movesets are public; nothing hidden in a match
Super Smash Bros. for Wii U
Tripping removed; only minor move RNG remains.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Mortal Kombat Trilogy
Knowing the bloated roster's broken tech is half the battle
Super Smash Bros. for Wii U
Rage mechanics and kill-confirm percents are deeply labbable.
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.