The middle-area on firebase Zero has to be the worst hack/upload spot in the game...we call it the "

Until Biowar reverse the hack mechanics, it's always going to be sheer luck on that spot.
I just had a similar situation on Derelict, I was feeding the Zerkers and Hydras rockets to get their attention, but they kept going toward the hack circle and just started to camp there.
That's why this "new" hack idea is so horrible. Skills barely matter if the game decides to fuck you.

I just try to draw aggro from the 'zerkers and heavies try to lead them away from the circle and around it. Keeping them alive as much as possible (we can deal with them after the objective clears) and hoping the teammates at the circle are able to manage themselves and draw not too much aggro from the biggies tailing me.
I succeeded doing yesterday's Platinum APEX wave 6 hack this way with the Insurgent, at the center-back on Paradox (it was the one placed behind the usual circle almost under the bridge, where the stairs are on the left. Probably just as challenging as yours on Zero).
I had to move in a crescent-shape, often going back the same way where I came from to keep the enemies as much out of the circle as possible. Shield boost helps...

I remember this one time *coughdarxtrydercough* on paradox when our team avenger got distracted on his way to the device and decided to kill an enemy instead and missed the objective by about a second. We wiped in wave 2.