While I know the general rules, I don’t argue with experts who tell me it’s CH3COOH instead of C4H2O2, and I don’t argue with the expert who tells me it’s CoVFeFe. We both know that even chemistry rules have exceptions.
You were right initially. Maybe not standard nomenclature but CoVFeFe is apparently a recognized synonym for Cobalt Vanadium Iron alloys which are “soft magnetic alloys” (i.e., alloys that can be easily magnetized and demagnetized).
Iron Cobalt Vanadium Alloy Synonyms
... FeCoV, CoVFe, CoVFeFe, VCoFe, FeVCo
https://www.americanelements.com/iron-cobalt-vanadium-alloy