Moving the conversation about Chambers’ stress injury here…
Growing pains are real, but not really connected to growth, and certainly not problematic or common enough to explain away a situation of this many of the kids having to have months out (or longer) due to stress related injuries as just something that happens with kids.
The most popular explanation for “growing pains” is the accumulation of stress related to physical activity their body isnt adapted to tolerate and recover from. To the degree that anything looking like growing pains is relevant in players at an age to be anywhere near senior football it is almost certainly a big mismatch in what they are being asked to do vs what they are capable of recovering from on a regular basis.