I mean.. we suspect there's a level of fabrication by early Roman historians. In your specific quote - it's more that record keeping (to that detail) happened after-the-fact and based on oral traditions. Just take a look at Suetonius and how he describes his sources of information, things along the lines of "well, this is hearsay but I heard it from my relative who knew XYZ and therefor I think it's credible".

Framing the uncertainty around early record keeping is a good. Similarly, the second Servile war in historic documents matches the first Servile war almost like Star Wars ep7 matches ep4. That _hints_ at fabrication. So if they fabricate data in one place.. :)