Thank you all for your informative input. Should we add to these-the ages of the young men and the processes in Athens for political and military training and duty (Arist. AC 42)-what little we can perhaps only surmise of Macedonian youths' military training? And this would have to do with Alexander.
And should we consider, as I think we are attempting to distinguish, or come close to what the ages of the Pages might have been (beginning and ending) in the service of the Macedonian king and his nobles, or generals (as they did serve them as well), the very young age (seven) of Spartan boys taken into their military service?
Perhaps there is, in both of these city-states and in the early life of Alexander in the Macedonian political and military world, information that may help us as they may have had some political and military influence on general Macedonian practices.
A few examples are: Alexander had at age sixteen the duty of regent of Macedon; at age eighteen, he was either sole commander, or in command with other of Philip's generals (whether on foot or on horseback [laughter]) as general at Chaeronea; and as a child he may have put specific military questions to the Persian ambasadors: if so, I think this suggests he was being educated in military and political matters from a very early age. This could have been something unique to Philip and Alexander, but also quite normal for a Macedonian prince. The Macedonian boy-king, Alexander IV, had Pages (Diod. 19.52.4), boys perhaps his own age, who were brought up with him. (It is not known, but is an interesting speculation if prince Alexander had Pages, and if any of these were his young nobles and later generals [as an example, in Alexander's case probably Hephaestion-who I believe was younger than Alexander by some months or a year or so], and/or if they [and Alexander himself?] served Philip as Pages). So I do think a Macedonian Page might have begun his service perhaps at the latest by age 14. Age 14 is what Hammond maintained, and Reames concurred, however she reminds us to be cutious in this, as we do not 'know'-no source gives specific ages for the Pages, and she says they may not have been as rigid as beginning at 14 and ending at 18-that they could have been younger, or older, and I agree.
I think the youths of Macedon actually may have begun their training in the Pages service at a younger age than 14, perhaps by a year or two or even more, and as a rule rather than as an exception. That the exceptions may pertain more to when they began in the service-perhaps as young as 12, or even younger (particularly if they were more closely associated in military practices with Sparta), but I'm not sure a young man would care (i.e. the humiliation) to graduate later than the rest of his same-age entry-mates, so perhaps up to 19 would have been quite acceptable (if we accept a less rigid age spread), but if not, then it seems 18 (or whatever age was 'set') would have been the absolute exit age for all of them.
I do agree that by age 20 (as it is Athenian-source attested), especially in Macedon, the young men would have been ready for the military.
Sincerely, hephalex.
ps. This is my first (and last? laughter) post. I have been reading letters and posts from 1998 (I am way too timid for my own good

, as a good, generous and courage-inspiring friend of mine on this forum will attest), and often thanking posters silently through the years. I shall thank you now for your service on this forum.