Except it can't be 100% random when Howitzer and Bomb Shelter seem to appear only on certain areas of the map. If you don't visit those areas, you won't find your SE's.
except a dev said that you wouldn't find a desert-type special encounter in a city tile, and vice versa.
How do I put this clear enough.They ---->USED TO<---- (meaning:an activity that was often repeated in the past but isn't happening anymore in the present) appear in certain areas.It was changed with one of the last updates.Now they are truly RANDOM.
Prove it?
try reading the changelogs
Pretty sure I'm up to date on changelogs, please source your information... you coming here to say "the information is out there" but not helping to find it, is being completely useless.