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

Execution · Pure Mechanics
An explosively destructible run-and-gun starring parody action-movie heroes.

Execution · Practiced Mastery
A co-op horde shooter about sniping waves of occult Nazi undead.
Broforce leans Execution (Pure Mechanics); Zombie Army 4: Dead War leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Broforce
Run-and-gun reflexes amid constant explosions
Zombie Army 4: Dead War
Long-range headshots and horde crowd control
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Broforce
Enemies are dumb scripts
Zombie Army 4: Dead War
Undead waves never adapt
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Broforce
Random bro assignments and destructible chaos shake runs
Zombie Army 4: Dead War
Spawn variation and elite placement shuffle runs
Zombie Army 4: Dead War leans a little harder on optimization, though the gap is small.
Broforce
Knowing each bro's kit and level layouts helps
Zombie Army 4: Dead War
Loadout perks, trap placement, score-chain knowledge
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.