head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is variance, 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.

Reads · Competitive PvP
Stripped-down RTS where fog of war and single-unit control reduce the game to reading opponent direction under uncertainty.
Command & Conquer: Red Alert 3 leans Reads (Grand Arena); Tooth and Tail leans Reads (Competitive PvP).
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
Tooth and Tail
Single-unit control under fog maps precisely to mechanical skill
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Command & Conquer: Red Alert 3
Three-faction asymmetry means opponent choices must be constantly predicted
Tooth and Tail
Opponent faction and expansion direction must be constantly predicted
Tooth and Tail leans a little harder on variance, though the gap is small.
Command & Conquer: Red Alert 3
Ore spawning and naval choke variance add moderate uncertainty
Tooth and Tail
Fog of war and food spawn placement create significant hidden info
Command & Conquer: Red Alert 3 leans a little harder on optimization, though the gap is small.
Command & Conquer: Red Alert 3
Production order and defensive placement are learnable but more flexible
Tooth and Tail
Factory sequencing and map choke selection are learnable but 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.