head to head
Overwatch asks more than Insurgency, and the gap is optimization.

Execution · Competitive PvP
Hardcore team shooter where one bullet kills and the HUD tells you nothing.

Execution · Grand Arena
Team hero shooter blending FPS mechanics with ability economy mind games.
Insurgency leans Execution (Competitive PvP); Overwatch 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.
Insurgency
One-shot lethality rewards precise aim
Overwatch
Hero aim, movement, and ability timing
Overwatch leans a little harder on reads, though the gap is small.
Insurgency
Human squads flank and adapt each round
Overwatch
Ult tracking, flanks, and baiting human teams
Insurgency leans a little harder on variance, though the gap is small.
Insurgency
No killcam or HUD hides enemy positions
Overwatch
Minor spread and matchmaking noise
Overwatch leans clearly harder on optimization.
Insurgency
Loadout points and objective route knowledge
Overwatch
Team comps, ult economy, and positioning theory
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.