I posted my II CO Legionary denarius of septimius Severus recently and noted in the thread that the obverse die was linked with multiple reverse types. I checked my notes and the die is linked with 10 different reverse types (not 9 as prevously mentioned). It should be noted that these are not just different reverse dies as there are a few examples where the reverse type is represented from multiple reverse dies too.
It should be noted that this isn't the busiest die and I believe thet Doug has seen an obverse die linked with a dozen reverse types.
I thought the topic worthy of a post illustrating my 6 examples thus far but also including the details of the other types too.
BONAE SPEI advancing l., BMC 341 pl. 15.12, Paris, formerly H J Berk stock, Martin Griffiths (multiple reverse dies used)

BONI EVENTVC (sic), Fides standing l., Bern, formerly Berk stock, Martin Griffiths (same die pair)

FELICITAS T[EMP]OR, wheat ear between two crossed cornucopias (B. Murphy stock, 2003)
INVICTO IMP TROPAEA, Trophy, Paris
INVICTO IMP TROPAEA II, Trophy, BMC 368 pl. 16.8
LEG VIII AVO (sic) TR P COS, eagle and standards, Oxford ex Walker, JNG 1978/1979, pl. 9, 4, Martin Griffiths (same die pair)

MINER VICT, Minerva seated left, holding victory in right hand, spear in left, shield beneath, Martin Griffiths

MONETAE AVG seated l. holding scales and cornucopia, Doug Smith, Martin Griffiths (x2) Multiple reverse dies

MONETAE AVG Standing l. holding scales and cornucopia,
ebay 2010
VICTOR IVST AVG, Victory adv. l. holding wreath and palm,
ebay ex. B. Murphy, Martin Griffiths

Regards,
Martin