Looks at the "how and why" of hoplite battle, and makes a lot of hamburger out of sacred cows in the process. He looks at the hoplite panoply critically, recreates it, and tests the prevailing wisdom using actual people armed as hoplites. Pretty convincing evidence that much of what we "know" about how hoplites fought is impractical, illogical, and occasionally, ridiculous.
Looks at the "how and why" of things by actually testing them; things like how were the spears made? Where was their point of balance? How were they held? Why was the shield that size and shape? How was it held? How did the hoplites stand in phalanx? Just how powerful was a spear thrust held in the different grips? How good was the armor at warding off said thrusts? Was the sauroter (aka lizard sticker) actually likely to be used in combat?
Not a book for the GD-level "hurr-durr" ad hominem mentality, because all of the Greek historians are taken to task, including Victor Davis Hanson. It is not a perfect book, but it is very enlightening, especially to those of us who like to know the "how and why".
A Storm Of Spears

Have you read it yourself?

I know spear lengths varied over time and the longer Macedonian pike had longer reach than the shorter ones wielded by the Lacadaemonians.  The longer Macedonian spears had to be wielded by two hands and the hoplon slung over the shoulder.  The earlier hoplites held their shield in the left hand and wielded the spear in the right.  

Another factor is mass.  The denser the line, the more the "shove" over the opponent.  It's one reason why the Lacadaemonians were defeated by the Thebans at Leutra.

By the time of Alexander the Great, less reliance was placed on body armor too.  Persian War era Hoplites wore bronze breast plates, greaves (shin guards), forearm guards and a helmet that protected the sides of the face.

I have read it myself, and thought it good enough to write a recommendation on it. Each of your questions / comments are addressed in the book.
As I noted, it's not a perfect book, but it gives a (IMO) much-needed technical view on the "how and why" of the panoply, without attempting to cover the strategic Big Picture.
A modern day analogy would be a technical treatise on WW2 Wehrmacht MG34/42 machine guns, showing how their design criteria were driven by small unit tactical doctrine, and how the gun's real-world employment in turn drove tactical doctrine.

Thanks!