To a certain extent I would say that any encounter your party blindly stumbles into is a good TPK chance. And one might expect that an average / casual player, esp. during their first playthrough, would generally follow this behavioural pattern. I certainly do
Sun Tzu teaches us that
Victorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win.
What this statement means is that starting a fight without knowing your enemy (numbers, positions, abilities, intentions, etc.) is a recipe for disaster. Scouting in particular, and military intelligence in general is so invaluable that it's impossible to overrate it. No military commander sane enough to tell their arse from their elbow would send their troops into an unknown territory.
This moment actually buggers me quite a lot in certain games, as designers seem to be forcing you to go the "scouting by combat" way. XCOM is particularly egregious at this (esp. the first one, because in xcom 2 I use the Long War mod which gives Shinobi).
First time I reached the village, for example, I did not recognise the ambush (or didn't pay attention) and got steamrolled pretty quickly. And if you just sneak around, the combat is 2 turns at most, sometimes just one. And that's exactly how it should be.
Know thy enemy, and never start a fair fight.
