The interesting part is knowing that the battle will soon be out of your hands. Put the wrong unit in the wrong place or burn a useful resource too early, and the mistake can follow you for the rest of the run. When a carefully arranged squad suddenly tears through a fight on its own, it feels deserved rather than random.
The unlocked full version gives you more room to tinker with unit mixes, upgrades, and resource-heavy builds. A single recruit can send a run down an entirely different road, which makes experimenting worthwhile. It has that pleasant sort of strategy where one good idea keeps getting better once the numbers start behaving.