Baby villagers move more slowly when playing than when wandering

Baby villagers are very slow when they are playing around, slower than when they are wandering. 

I checked the Doc in villager.json and find out that the play speed multiplier is 0.32:

"minecraft:behavior.play":

{ "priority": 8, "speed_multiplier": 0.32 }

}

On the Hard difficulty,  in desert villages sometimes Husk can easily infect baby villagers.