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.

Reads · Grand Arena
Three-faction Cold-War RTS with naval combat where faction asymmetry and multi-front pressure are the core tests.

Execution · Grand Arena
The beloved budget football sim whose play-calling chess still defines the genre's high point.
Command & Conquer: Red Alert 3 leans Reads (Grand Arena); ESPN NFL 2K5 leans Execution (Grand Arena).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Command & Conquer: Red Alert 3
Naval and air micro alongside base-building taxes player bandwidth
ESPN NFL 2K5
Stick skills on passes, jukes, and tackles
Command & Conquer: Red Alert 3 leans a little harder on reads, though the gap is small.
Command & Conquer: Red Alert 3
Three-faction asymmetry means opponent choices must be constantly predicted
ESPN NFL 2K5
Play-calling is a guessing duel against humans
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Command & Conquer: Red Alert 3
Ore spawning and naval choke variance add moderate uncertainty
ESPN NFL 2K5
Fumbles, tipped balls, and unseen play calls
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Command & Conquer: Red Alert 3
Production order and defensive placement are learnable but more flexible
ESPN NFL 2K5
Playbook mastery and franchise roster management
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.