What will have been “highly relevant” was a Macedonian heir, in Macedon and under the care of the Queen Mother and the European regent Antipater. The Macedonians’ dislike of Alexander’s “Persianising” was palpable and it would be a much frayed piece of “Old Rope” that missed the clear opportunity to press the heir presumtive’s chances (and his own) to the “masses”. The Atrax Robustus will not have been shy in baring fangs over those who saw matters differently. You seem too ready to discount the sway this woman had with the Macedones in the period after ATG’s death – without an heir in Macedonia.Nicator wrote:The old Macedon was now relegated to the position of a European province of the empire only. Perhaps the marshals still longed for the Macedon they used to know. But that was gone forever. This point is highly relevant concerning the Asian vs a Macedonian queen and any offspring forthwith.
Perdiccas (and others) only found the room to move due to the fact that no heir existed at the time of Alexander’s death. That room will have been seriously curtailed in the event of the above.
The sands through the hourglass were not as crucial as you make out. In the event, Alexander had plenty of time to conduct his campaigns throughout the north and into Greece. He also had time to re-arrange matters in the “Hellenic League”.Nicator wrote: And from the moment Philip's army took to the (Persian) field that clock was ticking (or rather...that sand was sifting through the hourglass). Certainly, the Persians bloodied nose from last time they attempted Greece kept her at bay for decades into the future, but with a European army making incursions into the Persian realm proper, Persia had to act. And the risk was that Persia might successfully resist and turn the tide back into Greece proper […] the Persians had to get mobilized quickly and prepare to resist. With a state the size of Persia, time was against Philip, ATG, & Macedon et al.
As well, the assembly and deployment of royal armies and fleets was not something accomplished in any short timeframe (as already pointed out and instanced by Issos). The question might be asked why the King didn’t assemble such given the Macedonian incursion. The answer would be that he didn’t see it as necessary.
As best we can guess, Philip had some 10-11,000 combatants operating in Asia Minor prior to his death. These troops were tasked with the old chestnut of “liberating the Greeks of Asia” and had met with mixed success. This task force is very often viewed in the reflected glow of the great invasion which followed under Alexander – therefore hindsight. The Great King did not necessarily see it that way and his reaction - the delegating of mercenary forces to meet the annoyance – shows this.
What is readily forgotten is that this was hardly the first such Greek army to “invade” the Empire. From Susa or Ecbatana the Great King might well be forgiven for ignoring the latest bout of pan-Hellenic claptrap emanating from the Balkans. In the aftermath of the Peloponnesian War (and Cyrus abortive rebellion) the Spartans sent armies under Dercyllidas, Thibron and Agesilaos. Agesilaos made great play of his intent to invade the Empire even unto aping Agamemnon. It turned into little more than raids on alternate satrapies. Later Thibron was killed and his army utterly defeated. All this handled by the local satraps.
The Great King might well be forgiven for viewing the latest pan-Hellenic outbreak with jaundiced, satrapal and mercenary eye.