Voted for spearmen; to me, it feels unrealistic to have more swordsmen than spearmen (perhaps I'm wrong, but then I don't know too much about Celtic warfare). The problem is that the Keltoi factions don't have great line spearmen like the Suebi or Dacians. Still, Gaelaiche are good enough for an effective army, especially when supported by a few Solduros (best Gallic unit IMO, apart from Carnutes).