Does coin alignment matter? Are Roman coins generally coin alignment vs medal alignment? Was there any intention (that we know of) on the coin makers to produce coins in any particular alignment?
"Most Roman coin types have a consistent die axis of either 0 or 180 degrees. Athenian tetradrachms almost always have a die rotation of 270 degrees. Some types do not show any consistency or pattern in die alignment." https://www.forumancientcoins.com/numiswiki/view.asp?key=axis
They usually tried to maintain an alignment like @Victor_Clark states, but it was not imperative. Other cultures changed orientations to facilitate striking of designs, especially thin coins like Sasanid issues. The higher the relief or thinner the flan and you are risking not striking properly, just like capped bust US halves and the reverse motto. Fully struck mottos are much scarcer due to metal needs of the obverse design.
Based on the Roman Republican silver coins in my collection, die alignment was random. The first 20 coins in my spreadsheet are: 5, 7, 3, 4, 3, 4.5, 7, 4, 7, 12, 9, 12, 4, 2, 4, 1.5, 3, 1.5, 11, 5 Roman and Italian cast bronze coins were mostly 12 (I'd guess 90%) with some at 6 and a few at 3. You can tell die rotation on many cast coins because they are not round. The top coin is 12 & the bottom coin is 6.
Sorry - this is just for "translators" or the German speaking community In around 2015 a scientific project was funded in Germany to research die-alignment with Roman Republican coins. Reason was Francois de Callatay's book "Les monnaies grecques et l'orientation des axes" for Greek coins Here a link to coinsweekly (German edition) https://muenzenwoche.de/neue-forschungen-zur-muenzpraegung-der-roemischen-republik/ and a link to a paper at academia (German too) as to the results https://tinyurl.com/26vxjcb6 Results were mostly negative. Coins struck by the same pair of dies sometimes showed the same alignment, and coins struck outside Rome sometimes showed alignment.
Later Byzantine coins have very consistent die-axes of 180 degrees. That turns out to be really useful when trying to decipher the undertype from overstrikes. As @rrdenarius noted, they is no consistency for Republican denarii. Numiswiki is written by regular collectors who can be wrong. In this case, the "die axis of either 0 or 180 degrees" is common in some time periods, but not generalizable to "Roman coin types." (especially if you count 11:00 to 1:00 as close enough to 12:00 and 5:00 to 7:00 as close enough to 6:00).
