head to head
Neither is simply harder - they are hard in different places. Arma Tactics demands more reads; The Elder Scrolls V: Skyrim demands more execution.

Optimization · Pure Optimization
A turn-based tactics game testing positioning and squad management under RNG.

Optimization · Pure Optimization
An open-world RPG mostly about discovering and stacking exploitable progression systems.
Arma Tactics leans Optimization (Pure Optimization); The Elder Scrolls V: Skyrim leans Optimization (Pure Optimization).
The Elder Scrolls V: Skyrim leans clearly harder on execution.
Arma Tactics
Turn-based - no twitch demands
The Elder Scrolls V: Skyrim
Combat is forgiving; aim and timing rarely punish you.
Arma Tactics leans clearly harder on reads.
Arma Tactics
Enemy AI scripted; some randomized objectives but no adaptive mind
The Elder Scrolls V: Skyrim
Enemy AI is scripted and exploitable; not adaptive.
Arma Tactics leans clearly harder on variance.
Arma Tactics
Hit chance and randomized missions add real randomness
The Elder Scrolls V: Skyrim
Loot tables and leveled lists inject mild randomness.
Arma Tactics leans a little harder on optimization, though the gap is small.
Arma Tactics
Positioning, cover and weapon use are the core tactics
The Elder Scrolls V: Skyrim
Skill stacking, enchant loops, and exploits are deeply 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.