Quote Originally Posted by Ryllharu View Post
As stated in the episode, Rimuru spent 10 days naming the orcs, got them all done in one go, and went into sleep mode for an unspecified amount of time after that.

And the names are like "Yellow-683M" and "Yellow-683F". They are precisely pre-planned, 1 second names.
It takes more than one second to say 'Yellow-683M', unless you go out of your way, which you wouldn't be able to keep up for long. Also add the time it takes for every orc to come up to rimuru. Realistically, we're looking at at least 10 seconds per orc.