I find it's the other way around generally speaking.
Hacking/talking/etc is really easy. It's Either you have the stats or you don't.
In most RPGs and FPSes, sneaking is more a test of patience then a test of smarts.
On the harder difficulty settings, for taking the action route, there's usually a bag of tricks that's not always obvious during the first playthrough.
They are easy only if you let it rely on the stats. If you make it a combination of stats and choice, especially with, ( I hate to say this) checkpoint saves, it becomes a lot harder.
Playing Dex recently, you can buy the Convince skill, which gives you conversation options with NPCs. Trick is, you have one of three choices and you have to pick the one msot likley to go with their particular personality as you've observed it ingame. I screwed up a bunch.
And, yes, checkpoints meant I wasn't going to restart from the level entrance.
Anyway, that's one way of doing it.
I find combat rarely to be smarts oriented. Reflexes and tactical sense, done. Vs AI, anyway.