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.

Optimization · Practiced Mastery
Sandbox warfare testing directional combat skill atop an optimisable army and trade economy.

Execution · Practiced Mastery
Looking Glass's 1996 squad-command sim of powered-armor combat on alien battlefields.
Mount & Blade leans Optimization (Practiced Mastery); Terra Nova: Strike Force Centauri leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Mount & Blade
Directional blocking and couched-lance timing demand real skill
Terra Nova: Strike Force Centauri
Piloting powered armor and aiming under fire is demanding
Mount & Blade leans a little harder on reads, though the gap is small.
Mount & Blade
AI lords and battle tactics are mappable scripts
Terra Nova: Strike Force Centauri
Enemy forces follow mission scripts, never adapt
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Mount & Blade
World events, prices and tournaments shuffle each campaign
Terra Nova: Strike Force Centauri
Unknown enemy placements on first mission attempts
Mount & Blade leans a little harder on optimization, though the gap is small.
Mount & Blade
Army composition, trade economy and fief management drive conquest
Terra Nova: Strike Force Centauri
Squad orders, loadouts and approach routes are plannable
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.