Why is it not a 1 v 1 game then? Why do we have parties? When we complain that a class is too OP we constantly get told that 'balance doesn't matter', 'this is a team game' and so forth... but IS IT a team game or not?
Well, if we look at 4e, the Warlord had proficiency in Cloth, Leather, Hide, Chainmail armor as well as Light Shield (but not heavy shield). They had weapon proficiencies in Simple Melee, military melee, but only simple ranged weapons. And they had a +1 bonus to FORT and WILL defenses (none for Reflex, so I don't think DEX save is a good idea).
Personally I prefer d10, like the Ranger. The Warlord is probably not going to invest into CON that much so I see them as naturally having less HP, without being too frail that they don't feel like trained warriors. The 4e Warlord had the same HP stats as the Ranger (12+CON at level 1, 5 per level, while the Fighter was at 15 and 6 respectively) so why not?