Pre-Game Meeting: Warm-up pitches

[Bluefoot]

NFHS Game. At conclusion of pre-game meeting, PU declares, "Five warm-up pitches for the first inning, then three warm-up pitches for the other innings - to speed the game along."

Both the NFHS and ASA(FP) rules allow 1 min. max for no more than 5 warmup pitches for all inning. Is the PU allowed to change this rule (to reduce the number of warm-up pitches) on his own? The game did not start late, and there were no impending weather or darkness issues to deal with, so I don't understand why the PU was concerned with 'speeding the game up.' Do any of you make this type of declaration in pre-game?