Paladin is already known as one of the best Tanky high AC builds. I think the charisma bonus to AC makes it better at level 3+.
With defense and a shield, maxing AC here is what you are looking at on a max AC build:
Level 3: 21 (same as plate)
Level 4: 22/24 (12 studded+2 shield+4 Dex+3Cha+1 defense+2 Defensive Duelist)
Level 5: 22/25
Level 8: 23/26
Level 9: 23/27
Level 12: 24/28
Level 13: 24/29
Level 16+: 25/31
Add Shield of Faith for 2 more!
That is without any magic and I think it is the best any character can do at those levels. A Bladesinger, running Bladesong and Haste with the shield spell only gets to 30 and only while those consumable resources are active. This guy is effectively 31 with a reaction all the time at level 16+.
With defense and a shield, maxing AC here is what you are looking at on a max AC build:
Level 3: 21 (same as plate)
Level 4: 22/24 (12 studded+2 shield+4 Dex+3Cha+1 defense+2 Defensive Duelist)
Level 5: 22/25
Level 8: 23/26
Level 9: 23/27
Level 12: 24/28
Level 13: 24/29
Level 16+: 25/31
Add Shield of Faith for 2 more!
That is without any magic and I think it is the best any character can do at those levels. A Bladesinger, running Bladesong and Haste with the shield spell only gets to 30 and only while those consumable resources are active. This guy is effectively 31 with a reaction all the time at level 16+.