Jacob, can you give an example of how one would "place more tiles on such areas" to get more out of the Mining Guild?
Also, regarding the two "building tags" on the upper right of the Mining Guild card. Why two? Is two better than one? I am about to embark on my first solo play, and maybe I just haven't seen this yet ' in action.'
You could place ocean tiles on the two areas containing 2 steel and 2 titanium respectively as ålacement bonuses. There are in total 10 areas on the board with steel or titanium bonuses, and Mining Guild gets its effect when you place a tile (city / greenery / ocean / special) on one of them.
The two Building tags are first and foremost thematic; the Mining Guild has a lot of infrastructure/mining on Mars already when the game begins. More, it helps them to get the Builder Milestone, and it makes Medical Lab better for them.