I seriously doubt if most players have ever played a game with ArmA-levels difficulty in combat.
Even Arma has a noticable level of exaggeration and you can "first aid" yourself back to full health (well, someone on your team can, if you're KO'd by a hit).
I'd say that's a pretty big assumption to make. Despite being pretty harsh, ArmA and Operation Flashpoint have always been pretty widely known and popular with a sizeable niche. (Even back when ArmA
was Operation Flashpoint.
) And there are plenty of other popular titles over the years that accomplish much the same approach (Rainbow Six, S.W.A.T., Ghost Recon, SCUM, Escape from Tarkov...)
I'd argue that most players are familiar with that style and are at least aware enough of how it works to know whether or not they'd be interested in playing that sort of game. The fact remains, though, that such titles, despite their popularity and success within their own audiences, have never really carried
mass appeal.
I'd imagine that CDPR is definitely aiming for mass appeal, much like TW3. Ideally, I'd make harsher combat an option. Give players a more "game" experience by default (more survivability, slower and more obvious fight resolution), but allow an option for much more definitive combat difficulty (2-3 second TTK, less effective max armor, maybe even "one shot, one kill" if a weakness is exploited).
EDIT: Worth adding, I was just considering, that the true challenge here is that it's virtually impossible to come up with a base system, balance that as much as possible...then go create a very different system, and try to
rebalance everything that way, as well. (It's why most games simply leave the combat systems mostly the same, and just increase global damage or hit-point pools.)