Does anybody know how the hell are you supposed to get the cannon "backpack" to stay on securely?

The peg and socket ont he backpack goes into Onslaught/Barricade's 5mm peg hole and Mini-Con port on his shoulders (which ends up on Bruticus' back when combined). However, the shoulder pieces and thus the pegs on Onslaught are space too far apart.

I can't push them inwards (as if it's some sort of Hasbro QC problem), because the panel for Colossus head has specifically-spaced holes to lock the chest into the torso. So the cannon backpack is only secured on one side if I lock the chest in. So I've decided to not bother locking the chest/head panel in so the backpack can fit. (I've noticed the beginnings of white stress marks already, so probably for the best). Fortunately the chest's joint is tight enough to hold the ehtire thing up



This is one of several design issues I have with this set.