I do think it’s a valid concern, and you definitely still get the “aliens standing around” but it’s lessened on classic compared to normal. On normal you can only fight 6 aliens at once as well, if you uncover more they run away. It’s not gameplay mechanics, it’s more a shackled AI to make it easier.
As I said I lost over an hour of play to a crash, which is why at the moment I wouldn’t do ironman mode, but just make myself play as ironman with save backups. On my new playthrough I’ve done 3 missions and lost 3 people so far. One was my assault squaddie, who move up to a building and shotgunned a sectoid, but in doing so uncovered a sectoid pod and was flanked twice, dead. The other two were rookies, on a UFO downed mission- the outsiders have plasma rifles and better aim than sectoids, shot both my women rookies (I’m trying to get a woman support squaddy to name after my wife). I got a swedish guy called Thor Berg, who started with massive health. Not going to rename him.
It is very very fun so far. Looking forward to delving in more over the weekend and unlocking more squad abilities and research.
biggest gripe apart from the crash is the sometimes weird animation you get where you can see someone, but the animation shows you shooting at them through a wall or whatever. Immersion breaking, but no gameplay effect.