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
Play-calling mind games against a human layered over stick execution and roster planning.

Reads · Grand Arena
Three-faction Cold-War RTS with naval combat where faction asymmetry and multi-front pressure are the core tests.
All-Pro Football 2K8 leans Execution (Competitive PvP); Command & Conquer: Red Alert 3 leans Reads (Grand Arena).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
All-Pro Football 2K8
Stick skills on passes, jukes and tackles decide individual plays
Command & Conquer: Red Alert 3
Naval and air micro alongside base-building taxes player bandwidth
Command & Conquer: Red Alert 3 leans a little harder on reads, though the gap is small.
All-Pro Football 2K8
Play-calling against a human is a genuine prediction duel
Command & Conquer: Red Alert 3
Three-faction asymmetry means opponent choices must be constantly predicted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
All-Pro Football 2K8
Catches, fumbles and matchup rolls add per-play noise
Command & Conquer: Red Alert 3
Ore spawning and naval choke variance add moderate uncertainty
Command & Conquer: Red Alert 3 leans a little harder on optimization, though the gap is small.
All-Pro Football 2K8
Roster construction and playbook knowledge set the floor
Command & Conquer: Red Alert 3
Production order and defensive placement are learnable but more flexible
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.