What if … Alexander had married before leaving for Asia and had produced a son?

It is often said that Alexander should have married before leaving for Asia in order to secure his posterity, but this seems a rather simplistic way to look at the succession problem his generals encountered at their king's untimely death.

Let's assume he had married and produced a son in Macedonia. The boy would have been eleven or twelve years old, still a minor and too young to rule his father's empire. We may also wonder what kind of boy he would have been, being raised by a Macedonian mother and probably with a lot of interference from Queen Olympias, Alexander's mother. Would he have grown up as a mammy boy? Would he have been interested in his father's campaigns and the army? We know that in his youth, Alexander was in part formed by his father's constant battles and was well trained, for that matter, since he was allowed to lead Philip's cavalry at Thebes as a 16-year-old boy. Where and how would this son of Alexander have acquired his military experience? Sure, Antipater, as Regent of Macedonia, could have taken charge, but based on his relationship with Olympias, this sounds very improbable. Maybe the boy's mother was a fierce and proud Macedonian in the style of Adea/Eurydice, who later married Arrhidaeus/Philip III. In that case, the boy would have had a chance to grow up among Antipater's soldiers and hence be prepared to follow in his father's footsteps.

Remains the matter of succession upon Alexander's death. The boy would have been made king alright, and the Successors had one worry less, but who would rule in his name pending his coming of age? Since he presumably lived in Pella, it seems evident that his mother or Antipater would rule in his name. Can we eliminate the interference of powerful Olympias? I'm afraid not.

So how could east meet west in this case? Even if the army truly accepted the regency by the boy's mother, I fail to see how she could have commanded that group of weathered generals in Asia. Even highly skilled and seasoned Antipater, who had not participated in any of his kings' campaigns in Asia and had never been there, had only a slim chance. Each of Alexander's generals in Babylon would stake his claim, meaning that the Succession War could not have been avoided after all. It might only be shortened since young Alexander IV would have come of age in six years or so.