Personally I prefer the Barb/Paladin but it's not really Joan of Arc is it?
So trying to work with your initial concept here is a look til lvl 4
level 4
Human, Warlord|Paladin
Warlord Leadership: Combat Leader (Hybrid)
Hybrid Warlord: Hybrid Warlord Will
Hybrid Paladin: Hybrid Paladin Reflex
Hybrid Talent: Commanding Presence (Hybrid)
Commanding Presence (Hybrid): Inspiring Presence (Hybrid): You can get Scale Armour with a feat, and have light shield proficiency already (and Plate later on if your heart is set on it), meaning you can pick up a true leader feature with you hybrid talent feat; It also goes along with your desire to boost party healing more: AP and ally heals 1/2 lvl + CHA (so this gets consistently better as it goes along as well)
Human Power Selection: Bonus At-Will Power
Background: Divinely Inspired (+2 to Religion): I think this fits better than Streetwise for Joan of Arc, and it means you don't feel like living INT at 11 is much of an issue.
FINAL ABILITY SCORES
Str 19, Con 14, Dex 8, Int 11, Wis 10, Cha 16. (I think STR, CHA with a boost to CON for HSurges and Access to Scale Armour is better than spreading yourself too thin and trying to boost INT as well)
STARTING ABILITY SCORES
Str 16, Con 14, Dex 8, Int 11, Wis 10, Cha 15.
AC: 21 Fort: 18 Reflex: 16 Will: 18
HP: 42 Surges: 10 Surge Value: 10
TRAINED SKILLS
Intimidate +10, Religion +9, Diplomacy +10, Athletics +11
UNTRAINED SKILLS
Acrobatics +1, Arcana +2, Bluff +5, Dungeoneering +2, Endurance +5, Heal +2, History +2, Insight +2, Nature +2, Perception +2, Stealth +1, Streetwise +5, Thievery +1
FEATS
Human: Armor Proficiency: Scale
Level 1: Heavy Blade Expertise : +1 ATk (so same as having 20 STR) and +2 AC vs OAtks, which makes getting where you have to be on the battlefield when enemies are in the way a little bit safer.
Level 2: Hybrid Talent
Level 4: Harlequin Style: This turns your Warlord's Brash Strike from situationally good to Really Good nearly all the time. You get a boost to AC vs enemy's attack = CHA (+3) which not only cancels out CAdv but gives you an extra +1 AC bonus against the attack. If you have a fighter in the group (likely with all hybrids), this is a great one to lay on when he has your target marked. As if they attack you, it triggers the fighter's challenge and they attack you with a -2, plus the fighter could smack them a second time with CAdv for the attack. If your DM refuses to ever take advantge of the free attack chance, you may want to retrain this, but hopefully that isn't the case.
POWERS
Bonus At-Will Power: Ardent Strike: Charge and Sanction Mark, leaving you free to lay your Divine Challenge on a second enemy next to you. Of course you can also attack your Divine Challenge target, then Charge away and Sanction a second target, sucking up an OAtk (but with +2 to AC from HBlade Ex feat)
Hybrid at-will 1: Strike of Hope: Leaving this as you want to be able to dish out THP
Hybrid at-will 1: Brash Assault: As explained above: You hit, give target a chance to hit you back,and then have someone smack them for smacking you; enhanced by feat
Hybrid encounter 1: Vengeance is Mine: This is really good when mixed with a defender's Mark. Often a DM will respect the Mark, meaning your going to get hit. So when that happens you get to use your Im. Reaction to smack them back. AND have an ally 5 away walk over, hopefully into flanking position and smack them as well! Brilliant! "Hit me and only me or feel the Wrath of my God! *Enemy punches you in the teeth* *Punch them back in the teeth* "The wrath of my god and the wrath of my frien d Mike" *Mike clobbers them in the back of the head*
Hybrid daily 1: Bastion of Defense: Not touching this either, as you want to be able to boost your allies, this achieves that.
Hybrid utility 2: Bless Weapon: Holy smoke! You become a Striker for all fight long: +1 Atk and dmg; +1d6 radiant dmg on all attacks til end of encounter ... and if the creature is vulnerable to radiant dmg ... you crit on 18-20! Yikes! Undead tremble!!!!
Hybrid encounter 3: Hold Fast: Okay damage and Immobilise til End of Next Turn; The cool thing about this power is it can be used instead of a MBA, which means when you Charge. Now check out your boots at the Bottom: Charge and Shift away! And they are stuck there with noone to fight!
ITEMS
Lvl 2 Dwarven Scale Armor +1: Free Action Heal yourself when the chips are down; someone correct me if I'm wrong but you can take free actions when its not even your turn,
Lvl 3: Inescapable Longsword +1: If you miss your next attack gets a +1 bonus; this is cumulative til you hit ... this helps with the accuracy you desire,
Lvl 3: Cloak of the Walking Wounded +1, When you are bloodied and use Second Wind you can spend 2 HSurges instead of one, meaning you are a hard man to take down! or should I say woman ... Joan right?
560gp: Boots of Adept Charging (heroic tier): Whenever you charge you are allowed to Shift 1 square afterwards. This can open up all sorts of tactical advantages, but it is especially good combined with Hold Fast
Anyway, hope that helps give you some ideas!
Have fun!!!