Yes, n-key rollover sometimes comes up. In practice, I've only had it become an issue in the wild either when more than one player is sharing the keyboard or, in some rare games, primarily simulators, where you might need to hold multiple keys.
So it's not like nobody experiences this problem.
That said.. how are you holding C to crouch? I assume for WASD movement. I just tried that and it's contorting my hand in weird and uncomfortable ways.
I shifted my hand to the right so that my middle finger is on D, my ring finger moved forward and back (WS), and pinky for A.
That evolved from gaming on a laptop where I'd just rock my index finger back to hit C or shift my thumb forward and rock back on the space bar to jump. I got disturbingly good at Q3Arena on a Powerbook G3, yes, using the track pad. It inspired some bad ergonomic habits. haha
Now I just use Ctrl.