Arcane Necromancy isn't really what you think it is. An arcane necromancer is generally a debuffer. One who inflicts negative status effects on enemies. Because of how undead minions are handled, it is usually only feasible to become a zombielord through the Cleric or Dread Necro classes. Also, in a group that large already, MORE creatures on the field will seriously bog down combat.
A bard is sorta the opposite. He gives out buffs to everyone in the party. Note that his powers are balanced on having 3 other party member, one of which would be a full caster, who would almost never make an attack roll. In a party as large as your with multiple physical damagers, a bard's contibution increases significantly.
Also, Dragon Disciple is HILARIOUS in all the wrong ways. Don't take it, but I would still recomend reading up on it for the lols.
Bards are better utility than Rogues. They have Use Magic Device AND their own spellcasting. Rogues however, deal more damage. With the right feats, they deal ALOT more damage. And they still have significant utility. However, they are usually very dependant on the other meelees to do damage(early on, the only way to get sneak attack is flanking) as well as to prevent them from going splat(meelee range+lower HD+light armor).
On a side note. Bards get a class feature that is literally just 'I know TONS of history/lore and some of it pertains to this very situation'.
Don't forget about ARCHETYPES. Bards and Rogues can play holy havok with archtypes.
http://www.giantitp.com/forums/showthread.php?p=12555815#post12555815
This oughta help you with archetyping.
