I'd be happy to say that these three are apparently the same
obverse die.
Don't be surprised if a more comprehensive (and difficult!)
search also reveals
a match for the
reverse die.
Such things are both
rare *and* not, depending on the particular issue, even
those from the same city.
That is to say that for some issues where only a few dies were used, and a
reasonable number of coins survive, then die links are more-or-less expected.
Whereas another issue where there are large numbers of dies and relatively
fewer coins survive, then a die-match is less expected, though not impossible.
Take Constantinian bronzes for example; huge numbers were issued, and who
knows how many dies were used. Except in cases of large, discrete
hoards, it
would be less than expected to easily find a die link.
Whereas in the cases of the many and varied die-studies of Greek coinages
that have been published, one would usually have some expectation of finding
matches, perhaps even for both dies.
Note also that we benefit from a HUGE number of coins illustrated on many
sites across the 'net, and provided one uses the ideal
search terms it should
be easier than ever to find such matches, if in fact they are present.
Walter
Holt