At that resolution a modern OS is likely to round up the delay to some energy-saving number, and the run queue is going to be so contended that even if the timers fired at the right time, there would be little guarantee the processes awoke in the desired order.

I think on Linux the granularity thing is true for e.g. nanosleep(), but there is also the POSIX clock_*() functions, which I think guarantee higher resolution.