I think the biggest issue was the lack of forward planning....

I think the biggest issue was the lack of forward planning. Monty/Degrussa was moving towards the end of their mine lives yet management didn't replace those tonnes. Yes they acquired Black Butte and Motheo but neither of those projects will be in production before Degrussa/Monty ore was exhausted. The derating of the stock started when it became apparent that there would be a copper production gap of 12 -18 months (Degrussa/Monty production ends and Motheo begins). Matsa closed the gap, but the market is not convinced that they can add to reserve life or improve the operations. Recent macro and geopolitical factors have not helped.
I still believe Matsa is a high quality asset, we have already seen reserve life extended and a little bit of feedback I have seen on the analysts visit to the operations has been positive. There is scope to optimise the mine and extend its life. Although they did indicate that it will take some time (12 months?), they are improving operating and development rates and better focus on exploration. You have to remember Trafigura are metal traders not miners and perhaps have a different agenda (operating costs not as important as having the metal to trade).
The rerating of the stock comes from making Matsa more efficient and delivering copper from Motheo. Kalahari can deliver growth, perhaps Montana should be sold so that it doesn't occupy management time. The focus needs to be on getting Matsa and Motheo right.