In a Tricycle
interview several years back, Thich Nhat Hanh is reported to have said that it is better to ordain young, before so many defilements and 'baggage' has set-in. I think that could be a good point, but I believe it has more to do with the individual person and the contents of the mind/consciousness. For example, a monk who ordains young at say age 12 or 13 might wonder and even regret about not trying out the householder life. Thoughts like 'what might I have been, what might I have achieved, what might it have been like to have a son or a daughter . . . '
The greatest monk I ever met and have known is Ven. Punnaji
and he ordained at age 38 after a householder life as a physician.