head to head
Tom Clancy's Rainbow Six: Vegas asks more than Guns of Icarus Online, and the gap is execution.

Reads · Mind & Math
A team airship battler testing crew coordination and outmaneuvering human captains.

Execution · Competitive PvP
Tactical gunfights testing aim, entry planning and prediction of human opponents online.
Guns of Icarus Online leans Reads (Mind & Math); Tom Clancy's Rainbow Six: Vegas leans Execution (Competitive PvP).
Tom Clancy's Rainbow Six: Vegas leans clearly harder on execution.
Guns of Icarus Online
Gunnery arcs and repair juggling need competent hands
Tom Clancy's Rainbow Six: Vegas
Aim and snap-to-cover gunplay punish slow hands
Guns of Icarus Online leans a little harder on reads, though the gap is small.
Guns of Icarus Online
Human captains feint, reposition and counter your ship tactics
Tom Clancy's Rainbow Six: Vegas
Multiplayer angles and pushes demand reading human opponents
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Guns of Icarus Online
Cloud cover hides ships briefly, little else random
Tom Clancy's Rainbow Six: Vegas
Terrorist hunt spawns vary modestly between runs
Guns of Icarus Online leans a little harder on optimization, though the gap is small.
Guns of Icarus Online
Loadouts, role coordination and positioning are deeply plannable
Tom Clancy's Rainbow Six: Vegas
Room-entry planning and map knowledge are studyable
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.