I'm probably going to make a Paladin with a versatile weapon and no shield. I want them to be able to cast spells in a simple RAW method.
I think this is the easiest way to go to ensure you can cast a spell with a free hand. Unfortunately, GW fighting style is suboptimal with anything other than a greatsword. Personally, I changed the fighting style to allow rerolls of the the 1-4 on a d10 and d12. It gives roughly the same bonus as rerolling 1-2 on 2d6. It's unfortunate the rule is written the way it is as allowing a reroll on a 1-4 on d10 and d12 in no way whatsoever is overpowered.