Training regimen for the soldiers of the Diadochi... is there any record of one?

[Brave Brave Sir Robin]

If I understand properly, units such as the Hetairoi and Pezhetairoi were land owners who were well off enough that they had the social status to be members of their respective military units, but also the time with which to train with other such men. Units like the Klerouchoi were military settlers who were invited to settle land and thus improve their social status with military service being part of the deal. I'm not so sure that they were strictly professional in a sense that their "occupation" was soldier, but they probably had a similar martial background to the post-Marian Roman legions.

[Ludens]

They probably didn't think of themselves as "professional warriors" anyway. "Professional" is a fairly modern concept. Hetairoi would have defined themselves as nobles; Pezhetairoi as settlers/farmers; pre-Marian legionaries as citizens doing their civic duty. Warfare was not their profession: it was a social obligation (though in the case of nobles it was their primary obligation).