head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Competitive PvP
Destructible-environment shooter with tight gunplay.

Execution · Competitive PvP
A tactical shooter where precise gunplay against human opposition is the deciding skill.
Battlefield: Bad Company 2 leans Execution (Competitive PvP); Counter-Strike: Condition Zero leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield: Bad Company 2
Bullet drop and recoil demand real aim
Counter-Strike: Condition Zero
aim and spray control decide duels
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield: Bad Company 2
Destruction and flanks punish positional reads
Counter-Strike: Condition Zero
predicting human opponent positioning
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield: Bad Company 2
Some vehicle/spawn randomness, mostly skill
Counter-Strike: Condition Zero
buy-round economy and drops vary slightly
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield: Bad Company 2
Class kits and gadgets optimize objectives
Counter-Strike: Condition Zero
economy management and utility usage solvable
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.