I know we touched on this in the main Matrix Revolutions thread, but having watched the film on DVD about a dozen times since getting it last week, I thought this bared closer discussion.
A thing that struck me about Zion's defensive strategy was that it was stupid.
There were three types of munitions used in the battle of the dock: good old fashioned bullets, those lightning guns, and rocket mounted low yield shells launched from handheld rocket launchers. The bullets were the primary means of defense against the attacking sentinels. They were mostly used by big guns on the arms of the APUs as well as several fixed emplacements. The lightning guns were used by the escorts of the boyscouts shipping ammo about. The shells were used against the diggers.
The fixed emplacements were doing an okay job, but those APUs are probably the most ineffective way of defending a stationary target. They are clunky and ungainly. Their lack of maneuverability means that they're mobility is only useful when you actually need to move them somewhere such as in an offensive strike. It doesn't help them in evasion. They are little better than a tank. Even worse, the APUs need boyscouts with wheelbarrows to resupply them with ammunition.
So rather than make an army of APUs for defense (the humans MO seems to be to attack through the matrix rather than in the real world), they should make a smeg load of fixed emplacements. It would be a better use of resources as you don't have to waste anything on mobility systems apart from making the emplacements swivel about a bit. The sentinels wouldn't be able to knock them over if they were embedded in the suprastructure. Also they could be fed ammo directly from the honkin' ammo supply warehouse.
The use of the shells to take out the diggers was good in principle, but they made it look like Little Rascals. There was no real coordination in the infantry. We saw the two heroines looking at where the digger was a then just scooting off to a place where they could get a good shot and shooting without support. They might have been more effective if the infantry has worked together in a coordinated attack from multiple flanks.
The attack on the second digger was thwarted because of the sentinels swarming around the digger blocking the rockets. With a coordinated attack, infantry could have gone at the sentinels with lightning guns while other would have launched multiple shells at the digger, improving the odds of a single hit.
Overall, it seems that Zion lacks any larger munitions. With rocket mounted larger munitions they could have attacked the entry point with greater effect, taking out a great number of the sentinels in a huge swarm. Given the sentinels' affectionate nature for each other and their desire to fly around in a stream, they could have been seriously damaged by large explosives.
After the Hammer repels the first attack, Mifune compains about the total loss of defenses due to the EMP. Hint: powerful war was waged long before the advent of electronics. Canon shells don't have to work with computers or electric motors. Motors don't either. A bit of TNP can work wonders without the need for electronics. Given that it seems all Zion arms seems to be electrically based, this seems like very poor tactical planning. Roger Ebert commented he thought the humans should have fought the machines in a more human manner. This also makes strategic sense. Electricity is the life force of the machines. To not be dependent on that same life force is a tactical advantage, especially given the use of EMPs by the humans. They can blow an EMP crippling the enemy while leaving your own forces untouched. The lack of an EMP is never explained either.