Different classes have different initial stats like HP, SP, Phy Atk, Magic Atk, etc, on level 1.
So I would create a stats database to save those different stats of each class.
Swordsman example:
{ jobId: 1001, str: 8, con: 9, int: 3, spr: 3, dex: 6, hp: 980, maxHp: 980, sp: 57, maxSp: 57, maxStamina: 25000, hpRecovery: 15, spRecovery: 6, minPhysicalAttack: 9, maxPhysicalAttack: 9, minSecondaryPhysicalAttack: 9, maxSecondaryPhysicalAttack: 9, minMagicAttack: 6, maxMagicAttack: 6, aoeAttackRatio: 4, accuracy: 8, blockPenetration: 3, criticalAttack: 8, criticalRate: 9, physicalDefense: 3, magicDefense: 3, aoeDefenseRatio: 1, evasion: 7, criticalResistance: 10, movimentSpeed: 30, maxCarryWeight: 5185 },
PS: In the screenshot, these are not the true stats, because I completed some collections. I would have to use an account that has no collections completed and is not using a token to get the real numbers.