A hexblade doesn't really approach combat in the exact same way as a fighter, because they aren't the same class and don't have the same abilities, or hit points. They can be turned into fantastic mobile flankers. But unless they give us hexblade or allow us to multiclass, we're better off building our warlocks into blaster casters or support casters, because they simply won't be effective as a melee fighter after level 5.
I'd love to see hexblade put into BG3, but then I'd also love to see the other XGE subclasses put in too. But if that doesn't happen I don't want warlock to get the ranger treatment, I don't like larian's homebrew subclasses very much. This issue with vanilla warlock being a relatively subpar melee fighter with pact of the blade was something that was known back in 2015 when the PHB first came out, and this is why I was a little concerned when larian said they were only going to do the PHB content.
