Phalangites.

[Paralus]

There is a narrative of "decline and fall" of phalanx which argues that the phalanx was a nimble and flexible beast in the time of Alexander the Great, well coordinated with cavalry and light troops, with a long but not too long pike. This narrative argues for a stultification of phalanx tactics, so that by the time the Romans march in, they encountered a far less effective version of the phalanx used with such effect by Philip and Alexander.

As with so many things, one size never fits all. Generally in the maturing of tactical systems aspects grow more technical or refined. Concomitant with that, other aspects may become hidebound and system rigidity sets in. The tactical abilities of the commanders also come into play. Probably the best metaphor there being the difference between two piano players, both trained but of differing talent: the instrument can only produce to the talent of its user. Ditto tactical systems.

That said, one has also to realise that the phalanx of Philip V at Kynoskephalai was hardly that of Alexander at Pelion. Philip had called up the old and the too young for this campaign where as that of Pelion was already a 'veteran' force. As well, the cavalry that Macedonia was able to muster in support was far from the days of Alexander III as the forces disposed by Doson at Sellasia eloquently testify to. Similarly, battlefield tactics had altered somewhat since Alexander's day. It is a great pity the preservation of Diodorus fails us for Ipsos for we should well have seen just what reliance there was on the phalanx at that time. We have really to wait for Raphia where the notion was clearly the bigger the phalanx the better. What seems to have happened is that the tactically flexible combined arms of Alexander's attacking wing had essentially devolved upon cavalry only with a massive phalangite block holding centre.

I tend to agree with Michael. The latter Hellenistic phalanx might well have just as tactically 'nimble' as that of Alexander's. That it certainly seems not to have been comes down to manpower problems and / or the tactical use of phalanx within Hellenistic armies. The latter comes down to the commanders.

We have attestation that it was attempted to make the pikes in front less lengthy than those in the back, so that more of them would be able to take part in the actual combat. However, this stepped variance of length also has its use. You see, it is not difficult to slip past one of those pike points but there is no point in doing so, if then you get to face another one pointing at you behind it and others waiting behind it for your next attempt to slip past.

We have what appear to be various attested lengths of the sarisa over the time of its use. Polybius is clear that the second century phalanx had five sarisa points projecting beyond the front rank. These were of diminishing distance due to the fact they were all of a length. I believe the notion that sarisa lengths in the first five (or four) ranks were 'staggered' so as to provide and even hedge of spear points is a modern notion. I cannot see any tactical advantage in it whatsoever; indeed there are only disadvantages one of which is immediately apparent. Once a front ranker is killed, his file mate takes his place. Over the course of battle several may die in a similar position resulting in sarisa lengths of (say) 20 feet to 14 feet occupying the front rank.

As for Alexander's drill outside of Pelion, varying sarisa lengths will have mad a mess of the resultant evolutions. The phalanx was a critter of uniformity and I don't see why such uniformity would not have extended to its weapon. Indeed, I'd think it critical that it was.