»hovercraft fleet«

Why was locke so dead set on having all of the fleet in zion during the attack? from the movies it looks like the ships really didnt do anything, in fact he was pissed when the hammer set off its emp.

Lock orders a full recall back to Zion so that he can brief everyone on the plan of defence for the upcoming Zion attack. An attack in the real makes operations in the Matrix a second priority to defending Zion.

The ships role was to cut the Machine army off before it reached Zion setting up a wall of EMP discharges once the Machines reached a set point. This plan didn't work however thanks to Bane setting off the Caduceus' EMP to soon and takeing out those ships in range. Thios created a hole and alerted the sentinels army to them and it was easy picking for an army that size to take out what ships remained active.

Lock was pissed about the Hammer coming in and blowing its EMP because as he said it took out every defence Zion had running at that time leaving them completely open for those few moments. Had the Machines attack sooner Zion would have been completely wiped out.