Alexander's battle formation?

[Spoofa]

What was alexander's early battle formation? before he got a bunch of horsearchers and other such, when he mainly had macedonians and greeks?

[Roy1991]

The phalanx formed the main battle line, and the holes between the speirae of the phalanx were likely occupied by peltastai.
The flanks of the phalanx would be protected by mobile infantry.

The hypaspistai (sp?) probably formed the joint between the phalanx and the cavalry, but this isn't certain.

[Watchman]

Basic division AFAIK: phalanx line in center, skirmishers forward, more mobile heavy infantry flanking phalanx, Hetairoi plus Alex plus sundry picked cavalry on the right wing (plus likely the Hypaspistai acting as the "link" with the phalanx - that'd have been the most logical place for the best heavy infantry anyway, withing ready reach of the supreme commander), other cavalry forming a defensive left wing. I understand he pretty much used that one in all the three famous set-piece battles.

[Veris]

Alexander had a general formation in each battle but every time it was adjusted for the specific nature of the situation. The whole concept was to anchor the army around the phalanx in the center while trying to find an opening for decisive companion charge. At Issus, Alexander saw the Persian left to be weak because archers were stationed in front of the infantry; at Gaugamela, Alexander drew the Persian cavalry to the wings, opening a hole in the joint to charge the Persian center; at the Hydapses, Alexander used a force of cavalry to threaten the Indian flank and then charged the Indian cavalry when they were starting to move away. I don't want to bother speculating on what happened at the Granicus.

The general order had the phalanx in the center, the agema to the right of the phalanx, the companions in the center-right reserve, with the extended right wing having the mercenaries, the medium and light cavalry, and sometimes the light infantry (mainly peltasts, missile units and agrianes) at an oblique angle to the formation. The left, while still under Parmenio's command, had the Thessalonian cavalry along with more of the mercenary and the rest of the cavalry and light infantry. Alexander never used too much of a reserve, for he rarely ever had manpower to spare.