The big problem with TLJ is that Ryan Johnson doesn't know how shields work. While you can indeed focus your shields to a particular point of the ship, squadrons and ships can't just get trough the shield at a high speed like Poe's X-wing or the Raddus. Squadrons could get trough the shields in earlier movies after the ship had already taken some damage. While Poe's x-wing just gets trough the shields at a high speed no problem. Remember the X-wings in rogue one trying to get trough the shield gate? It didn't end well for the pilots. There is literally a clone wars episode in wich is explained that fast moving thermal detonators can't get trough shields while slow moving one's can. Why else did the droids slow down while entering the shield on the battle of Naboo. While crude weapons can get trough shields, both X-wings and the Raddus aren't crude projectiles. They're just fast moving vehicles that should get destroyed on impact like the x-wings on Scarif or the other fighters at the battle of Endor (do you see any damage to the star destroyers they crash into?).