You can achieve very high armor without much of anything for armor. We have someone who went dragon disciple in our group, and with all feats, fighting full defensive etc.. he gets somewhere around 50AC with no armor. He has like 8 or 9 dex bonus, +3 natural from Dragon Disciple, he is a 6 sorc/4 fighter/7 dragon disciple. He has a +3 shield (5 ac), and a Rapier +4 of Defense. He always keeps Mage Armor up, Ring of protection +2, Necklace of Natural Armor +4
So right there he has:
10 - Base
7 - Natural (3 from DD, 4 from necklace)
9 - Dex
5 - Shield
2 - Ring
4 - Weapon
2 - Defensive
5 - Combat Expertise
44 AC fighting Defensive + Combat Expertise. Full Defensive he gets more. Mage Armor wasn't listed in those calculations because it doesn't stack with one of the other items he has, but he keeps it up for the ethereal protection.
He also has like 19 points in tumble, so if he is tumbling, he gets +3 to AC (+1 for every 5 points in Tumble)
Once again, there are always ways of manipulating skills and combining them with items to get maximum output. His character can block hits with his AC like a mofo... his only problem is he doesn't put out the damage, so when he hits for 20, and the rogue hits for 200, the dragon says "Screw you, I'm hungry for Orc Rogue"...
Just let it play out. You'd be suprised, some characters don't come out of their shell until higher levels (like casters) while others gain power early, but it ramps up slower, allowing you to catch up. You should see when Dervs get to like level 9 or 10 derv skill, level 15 or 16 total... with skills and abilities etc.. our derv like once or twice per day, can bust out 11 attacks in one round. Works great when we put Fires of Purity on him =)