If a region is adjacent to or contains more than one source of Invaders, do you add more than one Explorer?
If a region is adjacent to or contains more than one source of Invaders, do you add more than one Explorer?
No, you only add one Explorer if there is a source of Invaders, regardless of how many Cities, Towns, or Oceans are around or in it. (See p. 10 and Explore Examples C and D on p. 11)