The strategy is simple here: Mushin out either the Overwriter or Mandatory Upgrades. Add another advancement to it to raise the stakes, or sometimes add ice in front to throw the runner off. The point is to keep them off kilter either way. If/when you score Mandatory Upgrades, it should be pretty easy to score other agendas from then on. If you land a hit with Overwriter, then Neural EMP + Archived Memories is there to help you finish the job.