Under 5 years old, an age difference of 2+ months can already be a major advantage in any sport that requires coordination, dexterity, anticipation, and agility without even considering raw talent. There's a documented phenomenon where leagues that start splitting kids into skill levels at a young age are split predominantly based on the proximity of the month the kids were born to the age cutoff. Being older is already a massive advantage around then because their brains and bodies are developing rapidly and a few extra months of development has a lot of effect on their cognitive and physical abilities, and their height and weight.

This kid may be an outlier in raw skill. But honestly that also may even out considerably as other kids' motor skills develop. This shit is temporary and part of playing sports in this age range. All of the people involved need to just chill out and watch the kids play whether they are killing it or chasing the ball.