that's the thing. every ship is connected to zion's mainframe, even if to simply just open the gates, it is connected none-the-less. our computers get viruses from outta nowhere... especially worms. every living creature, atrificial or not, will find a way to exert the least level of energy to complete any task... why would the machines wanna go the hard way? they wouldn't need the diggers, they would simply open the doors and unleash hell. and how many gates were there? 3 was it... or more? imagine the mere volume of sentinels pouriong into 3 big a$$ gates instead of one measly hole.