If you wish to use the definition you earlier quoted, the word competitive is redundant as you say it applies to every league/competition.
Do you think a one horse league is 'competitive'?
So when you said... 'let him test himself in a competitive league' it was meaningless to use competitive... because that term could be applied to him being loaned to literally any league he is eligible to play in! Including playing as an overage player in our under 23 team. 🙄