Good point.
In retrospect, my comment "does not make much difference to the game in the long run" was made with the full version in mind.
From playing a similar small version on another site, I will agree that advance knowledge of the volcano placement, could at times give too much of an advantage on the small version. It would be allowing that person the chance to not only establish position within the opponents territory, but also restrict the opponents ability for movement. Very important in the mini, ...err, small version.