There could be many coins struck with the same stamp. A coin is discovered in an event. A coin can have been found isolated or in a hoard. Obviously, all the coins in the same hoard have been discovered in the same event, but is not necessarly true that two coins discovered in the same event are part of a hoard. A coin or a set of coins could be published in one or more numismatic papers.
Many coins can have the same type and be stored in the same museum.
A coin is either an isolated coin or a hoard coin. Both isolated and hoard coins are discovered in some events, but, of course, all the coins in a certain hoard were discovered in the same event. Moreover, many coins can belong to a specific hoard and be discovered in a specific event although not all the time there exist records about these events. Similarly, in a certain place can have occured more than one event.