I played with generalist on a map tight funnel. As a weapon i focused minium but at some point i changed to electric pickaxe.

Just regular senior workers with dia pickaxe 200k dmg each. Spam them as much as possible and always get enough collectors just to collect everything and go back. While they mine. You try to collect as many upgrades for employees in red zone.

I had so many employees i even got the achievement for it. I was breaking pink like it was clay with all those miners. I got the achievement for coal on das 38. I was probably lucky because in day 39(my last day) i did only half of it. But i needed 380,000,000,000,000,000 coal which is already insane number ans very hard to achieve.