Recently, the new trailer for Terminator Genisys (Because 'y' is cooler than 'i') came out. I, personally, liked it. That's all I'm going to say about it, because there's not much to say besides "I liked it."

Anyway, with Terminator on my mind, a question occured to me: Why doesn't Skynet send multiple Terminators back in time? The first time, I can understand why not. Hell, the second time, I can understand why: you have a freaking liquid metal robotic killing machine. But the third time? Especially if this robot is going after multiple targets. Just send a few liquid metal Terminators back in time. Boom. Problem solved. Seriously, for an artificial intelligence with no emotion and a desire to eradicate humanity, Skynet has an arrogance that's almost human.

But, seriously, why hasn't Skynet sent multiple Terminators back in time to the same point? Is there a canon reason for it? (Yes, I know, Genisys has multiple Terminators sent back in time. But that's a semi-reboot a la J.J. Abrams Star Trek.) Please let me know: is it stupidity on Skynet's (and the writers') part, or is there a good reason?