Lead-off Batter = On-Deck Batter?

[Manny A]

Okay, so this might sound like an inane question. But here goes:

NFHS. In between innings, how many batters may the offense have outside the dugout swinging a bat? As PU, I'm constantly policing areas in front of the offense's dugout when I see the lead-off batter and the upcoming on-deck batter taking their cuts. I tell them, "Only one batter out of the dugout, Coach." In response, I'm met with looks of utter confusion.

Looking at the NFHS rule book under 2-5-3, it says, "A single on-deck batter shall remain in her team's on-deck circle while the opposing pitcher is warming up." To me, that means the lead-off batter is the only player allowed outside the dugout swinging the bat.

Or does it?

The definition of On-deck Batter in 2-5-3 doesn't really help. It just says it's the player entitled to occupy the on-deck circle. Great; that's really on point...