OLD s.v. Thūȳdidēs cites a plural ~ās from Cicero's Orator 32. Section 30 is cited for Thūȳdidēus (-īus) '(masc. as sb.) an imitator of Thucydides'.
 Ecce autem aliqui se Thucydidios esse profitentur: novum quoddam imperitorum et inauditum genus. Nam qui Lysiam sequuntur, causidicum quendam sequuntur non illum quidem amplum atque grandem, subtilem et elegantem tamen et qui in forensibus causis possit praeclare consistere. Thucydides autem res gestas et bella narrat et proelia, graviter sane et probe, sed nihil ab eo transferri potest ad forensem usum et publicum. Ipsae illae contiones ita multas habent obscuras abditasque sententias vix ut intellegantur; quod est in oratione civili vitium vel maximum.  Quae est autem in hominibus tanta perversitas, ut inventis frugibus glande vescantur? An victus hominum Atheniensium beneficio excoli potuit, oratio non potuit? Quis Porro umquam Graecorum rhetorum a Thucydide quicquam duxit? "At laudatus est ab omnibus." Fateor; sed ita ut rerum explicator prudens severus gravis; non ut in iudiciis versaret causas, sed ut in historiis bella narraret;  itaque numquam est numeratus orator, nec vero, si historiam non scripsisset, nomen eius exstaret, cum praesertim fuisset honoratus et nobilis. Huius tamen nemo neque verborum neque sententiarum gravitatem imitatur, sed cum mutila quaedam et hiantia locuti sunt, quae vel sine magistro facere potuerunt, germanos se putant esse Thucydidas. Nactus sum etiam qui Xenophontis similem esse se cuperet, cuius sermo est ille quidem melle dulcior, sed a forensi strepitu remotissimus.
Yonge: "But some people—quite a new and unprecedented body of ignorant men—profess themselves imitators of Thucydides. Now those who take Lysias for their model are copying a great lawyer; not indeed the greatest and most dignified of speakers, but still subtle and elegant, and a man who may well hold his ground in all forensic discussions. But Thucydides, indeed, relates affairs of history, and battles, and wars with great dignity and excellence; but nothing can be borrowed from him for forensic or statesmanlike purposes of oratory. And those very speeches which he gives have many obscure and hard sentences in them, so as scarcely to be intelligible; and that is the greatest possible fault in an oration addressed to a man’s fellow-citizens. But how is it that there is such a perverseness of taste in men, that after they have got corn they persist in feeding on acorns? Shall we say that the food of men could be found out by the assistance of the Athenians, but that eloquence could not? Moreover,  which of the Greek rhetoricians ever drew any of his rules from Thucydides? Oh, but he is praised universally. I admit that; but it is on the ground that he is a wise, conscientious, dignified relater of facts; not that he was pleading causes before tribunals, but that he was relating wars in a history. Therefore, he was never accounted an orator; nor, indeed, should we have ever heard of his name if he had not written a history, though he was a man of eminently high character and of noble birth. But no one ever imitates the dignity of his language or of his sentiments; but when they have used some disjointed and unconnected expressions, which they might have done without any teacher at all, then they think that they are akin to Thucydides. I have met men too who were anxious to resemble Xenophon; whose style is, indeed, sweeter than honey, but as unlike as possible to the noisy style of the forum.".
Pl.Tht.169b (Ἡρακλέες τε καὶ Θησέες) crossed my path again this week.