מראשׁ פרעות אויב...
The first challenge is that its poetry, and thus terse and minimalist.
The words in question are these last three of the verse (which read in Hebrew R-->L)
The first is a compound: from (mem preformative) [the] head/top/first (as in Rosh Hashana, the first/beginning of the year)
Second, the word that invites disparity of meaning.
1) "locks" (of hair) In Num.6:5 you have a masc. form of the word closely associated with "head" again, ref. the Nazirite not to shave the "locks of the hair of his head."
2) The words seems to derive from a root word, meaning "loosened" "unbound" "primitive condition," which may relate it to the verbal idea of "lead".
Maybe there was a connection (supposed?) to "wild" fighters, who "led" charges against foes, I'm not so sure. The KJV seems to use this kind of "let loose against" here, and in Jud.5:2, with the idea of "vengeance." In the last, the ESV goes with "leaders, leading"
3) maybe a unique rendering of the root, Prv.4:15, "avoid"
There is another place using the root word, familiar to many, Prv.29:18, which the KJV translated, "where there is no vision, the people perish." Most newer translations go back to the idea of "loosen," rendering it, "...the people act without restraint." This fits well with the use Ex.32:35.
Finally, the third word means enemy/adversary/hated (one)
Put together, you have: from the head {loosened} enemy. Very terse, enigmatic phrasing. Often requires a good contextual read to even make something like that intelligible to us. But I think you can make out how that middle term is variously put into play with the other two in the different translations. Sometimes two of the words are made into modifiers of the other. Sometimes one is made adjectival to one other, which is put in construct-chain with the remaining.
Hebrew can be challenging.