Date is obscure (see Farrington); 450 BCE is the date before which the first Isthmian ode is written (cf. Odes. Pindar. Diane Arnson Svarlien. 1990) and therefore serves as a terminus ante quem for the victories.
Farrington n. 679 writes: 'Pindar, Isthm. 1.11, reads ‘ἐπεὶ στεφάνους ἐξ ὤπασεν Κάδμου στρατῷ’. The subject of the verb may be either the isthmus itself, Herodotos, who is the honorand of the ode, or Apollo, the presiding deity of athletic life (...). The phrase ‘Κάδμου στρατῷ’ (...), however, may be a reference, in metaphorical terms, to athletes from Thebes, although the date and nature of their activity is completely obscure.
Since taking Κάδμου στρατῷ as a metaphor for Theban athletes is doubtful, Farrington has categorized the victories under 'doubtful groups of isthmionikai'.