Its not fully clear how many medals are required to have a medal on all possible maps. (I believe it is currently 114 (105 countries, 9 other classic maps). Adding the progress bar back from the explorer mode page (which is still accessible through the link) would work to solve this, but also adding the number of maps required to reach 100%. On top of this, the achievement "Explorer Mode: ____" should include the continent based maps as well to progress the tiers.