I was fiddling with energon Bruticus last night and came up with the following configuration.
Attachment 1524
I used my five-year-old son's Strongarm for the right leg. His Stongrarm has only one arm so I don't know if it's on both arms, but the arm has a small hole in it that fits on to the small pegs that are on the back of one of Barricade/Onslaught's legs.
Attachment 1525
It's not the securest of fittings but for display it's fine.
As for the left arm, I opened up the door panel on the back of Barricade/Onslaught and wedged a helicopter arm in. These is even less secure and as you can see I havent managed to fit a hand on.
Attachment 1526
This is looking down on top of Bruticus. His head is in the lower left corner.
Maybe someone here can figure something out.....