head to head
Neither is simply harder - they are hard in different places. Super Smash Bros. Melee demands more execution; Worms Clan Wars demands more variance.

Execution · Competitive PvP
A platform fighter with one of the highest execution ceilings in any competitive game, layered on top of deep human reads.

Execution · Competitive PvP
Artillery aim and turn planning against human opponents on destructible terrain.
Super Smash Bros. Melee leans Execution (Competitive PvP); Worms Clan Wars leans Execution (Competitive PvP).
Super Smash Bros. Melee leans clearly harder on execution.
Super Smash Bros. Melee
Wavedashing, L-cancels, and tech-chasing set an extreme physical ceiling
Worms Clan Wars
Grenade arcs and ninja-rope control decide turns
Super Smash Bros. Melee leans clearly harder on reads.
Super Smash Bros. Melee
Reading DI choices and opponent adaptive habits is constant and non-convergent
Worms Clan Wars
Anticipating human opponents' target priorities matters in clan play
Worms Clan Wars leans clearly harder on variance.
Super Smash Bros. Melee
Stage hazard RNG and spawn positions add marginal chaos
Worms Clan Wars
Crate drops and terrain destruction add swing
Super Smash Bros. Melee leans a little harder on optimization, though the gap is small.
Super Smash Bros. Melee
Character matchup tiers and optimal movement routing are deeply studied
Worms Clan Wars
Weapon economy and positioning plans reward forethought
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.