Purely anecdote on my part but on the last character I was levelling with Lokarr’s set through Ultimate, those Arkovian boars were chunking me with Physical/Trauma damage almost as badly as the Shamblers were.
I might be misremembering but didn’t the base game enemies/bosses get a buff to bring them up to Ashes of Malmouth/Forgotten Gods level awhile ago?. Around the same time as the Veteran buff. Might be a result of that, they definitely seem scarier than I remember recently.