My first achievement guide, and turns out this achievement was pretty harmless though it takes some tries.
If you don't have the Skull Combo cheevo yet it will come as a bonus.
What I did actually was purchasing the sniper rifle (With reference to the rocket launcher solution above) at the place of the magnum, and the damage boost up extra with a start currency of around 3000 XP, which made it really simple (You can demolish one Wrath with just 2 shots).
Take out the first gang with the plasma turret, then just use the SMG's on the small guys, and the sniper rifle on the vehicles and the bigger guys.
Only tricky is the last part, but even that felt simple.
Remember to take it slow, and always have in mind that the retries are endless.
I didn't use either the cloak or the overshield boost up, but it's all your choice how you want to attempt this 30 worth achievement.
Good luck!