I managed for the first time to do this fight with no cheese (no sleep potions, no barrels, no highground, stealth abuse) I did however call in the help of Ogres, that soaked some damage for me. Would be dead otherwise I think.

However, with their help I found the encounter very enjoyable. I do think the artificial boost to Giths is frustrating - it's way out of line to not be jarring. Doing the fight using spells, scrolls and personal buffs and not dealing with shove, highground nonesense or abusing stealth was satisfying. Only reinforced me in conviction that if Larian dumped their homebrew it would be a far more satisfying game to play.