The numbers may be good but, In my opinion, they are a result of many outside factors rather than some ”brilliant” strategy that was implemented by MB and her leadership. I imagine the severe cost-cutting had its influence on the numbers as well. Strong truck sales played an important role but let’s not forget that truck production has a long tradition at GM and that people are used to buying those types of vehicles. Outside of that area, basically every new project that wasn't a truck or an SUV went down the drain. Good luck keeping those numbers with a smaller workforce and the talent that went out the door.
https://www.cnbc.com/2019/02/06/general-motors-q4-2018-earnings.html