L. Caeciliō Metellō C. Fūriō Pacilō cōnsulibus, Metellus in Siciliā Āfrōrum ducem cum centum trīgintā elephantīs et magnīs cōpiīs venientem superāvit, vīgintī mīlia hostium cecīdit, sex et vīgintī elephantōs cēpit, reliquōs errantēs per Numidās, quōs in auxilium habēbat, collēgit et Rōmam dēdūxit ingentī pompā, cum elephantōrum numerus omnia itinera implērent.
In the consulship of Lucius Caecilius Metellus and Caius Furius Pacilus, Metellus defeated a general of the Africans in Sicily, who came against him with a hundred and thirty elephants and a numerous army, slew twenty thousand of the enemy, took six and twenty elephants, collected the rest, which were dispersed, with the aid of the Numidians whom he had to assist him, and brought them to Rome in a vast procession, filling all the roads with elephants, to the number of a hundred and thirty.
What is cum doing in the last clause? I know the translator rendered it ‘with,’ but elephantōrum is in the genitive, and it seems like that clause can stand alone without cum.
cum + subjunctive is a very common form to indicate a causal or semi-causal clause. You would choose the tense of the subjunctive according to the consecutio temporum
For fun I did a little search and there seem to be multiple issues here.
-your translation is working with a different version of Eutropius, since it gives the number of elephants a second time (e.g. compare the text on thelatinlibrary.com, which is the Teubner edition, which has: cum CXXX elephantorum numerus omnia itinera compleret).
-the verb in Roma Aeterna is in the plural. This is very odd, I couldn’t find that in any version of Eutropius in my quick search. It would make the most sense if Metellus stayed the subject. Maybe it’s a typo?
-other versions of Eutropius have an entirely different construction, e.g.: cum centum triginta elephantorum numero omnia itinera compleret.
Thanks for your digging. I double-checked my write up of this sentence, and it is exactly what Roma Aeterna has on the page; if there’s a typo, it’s from Hans Orberg. In fairness to him, this would be the first one I’ve encountered in Roma Aeterna.
The last version you listed, cum centum triginta elephantorum numero omnia itinera compleret, seems to be what my translator worked from.