You have to get real lucky for Be More Objective, really. I've watched tons of tutorials on youtube and read here on the forum and copied it to the best of my abilities, but it simply doesn't work. The Hacking part is the toughest one and people simply rush the Hackbox and go hide by the Command Post and hack it from 0 to 100%.
I just can't do that, the enemy AI won't leave the Hackbox alone... It all seems so random.
If you manage to go Heavy, and incapacitate the entire enemy team - NO KILLS - right before you start the hack, I've found that helps A LOT.
It gives you a short delay before they take the spawn wave, which means you have time to get into position, and it gives your teammates time to rush about being derps before the enemies show up. Then their job is simply to be easier targets than you or the hackbox for a couple of minutes.
It's far from foolproof, but it worked for me on my 2nd try.
Haven't gone for any of the 3 star ones yet though.