I ended up going defense fighting style for the free +1 AC. Great Weapon Fighting Style for rerolling a 1 or 2 on the weapon damage doesn‘t seem significant enough . But a 2nd and then 3rd attack with the strength bonus seems worth vs an ASI. Level 8 will be an ASI. Haven‘t quite made it 4, so haven’t gotten to test if Follow-up Strike works with a versatile weapon in 2 hands. Later in the game having a good 2-hander seems likely, but early game, not so much. I do agree that ranged weaponry on a Paladin is pretty meh, so I run like you do with a 1-hander plus shield in one slot and 2-hander in other. None of the Solasta Fighter subclasses interest me, so probably won’t be using one of those anytime soon.
Its not necessarily that,
Its that you have to understand Paladin.
The reason for Great Weapon style and rerolling 1s and 2s is that your average damage will be much higher. So you won't get the extreme low on a bad dice roll. But that's only part of it, and you tend to get the High Damage end more often.
EXAMPLE: A dice roll that starts at two 1s ends up being a 4 and a 6 for 10 damage plus strength.
The second part is that Paladins and the number of attacks they have increases the number of Smites that can be used. Follow Up Strike is a bonus attack. So they get 2 attacks at 4th level and 3 attacks at 5th level for 3 total Smites, Combined it with higher average weapon damage from Great Sword Fighting Style and the Paladin turns into a monster for damage burst when you need high single target damage.
Plus they can also swap back to Sword/Shield in the other slot and go all defensive if needed and its only one AC less than with Defensive Style.
Its is significantly more damage than either a Ranger or Rogue can do.
Hence why GWF Paladin is considered the best configuration.