Let's start with the fundamentals of armor mixing, since this can really impact your combat effectiveness. The most crucial thing to watch for is proficiency requirements because equipping any piece you're not trained in triggers disadvantage across all your actions, and you definitely don't want that during intense fights. Each armor slot needs its own proficiency check, so mixing a heavy chest piece without proper training will mess you up even if you're good with light armor everywhere else.

Dexterity bonuses are super specific with timing windows - light pieces let you use full dex bonus which is great for nimble builds, medium caps at +2, and heavy just ignores it completely. The tricky part comes when mixing these since each piece calculates separately. Maybe interesting: some specialized gear combinations actually work better together like the Helldusk set where the heavy pieces sync up with fire damage bonuses from certain headpieces, and positioning yourself to maximize these bonuses becomes key during fights.

Your stealth approach matters too because even one heavy piece will give you away - the moment you equip heavy armor that stealth disadvantage kicks in regardless of what other light or medium pieces you're wearing. Getting the timing right on your movement becomes way more critical especially if you're trying to maintain combat advantage. The sweet spot usually comes from either going all-in on one armor type or carefully planning hybrid setups through specific feat choices, just remember you're trading other potential upgrades to make that work.