Ok, we're probably overthinking this, but spears. They can attack from the second rank. Now my group had an argument that this means you need an ally between you and the target (ie the first rank), others thought that you could attack an enemy with an empty 5ft square between you both (like reach i DnD).
the spear's long reach is simulated by the rule on p. 101 of the core ACKs rulebook:
> A combatant using a weapon with a long reach (spears, for
> instance) may choose to attack a closing opponent on the
> closing opponent’s number and thus attack simultaneously with
> the opponent, even if the combatant rolled lower for initiative.
> Likewise, if a combatant has a missile weapon readied at the
> beginning of round and is not engaged in melee, he can fire at a
> closing opponent on the closing opponent’s number even if the
> combatant rolled lower for initiative.
so the advantage a reach spread grants you is that, no matter what you roll on initiative, you at least get to attack simultaneously with the person closing the distance to hit you.
Spears are intentionally an awesome weapon in ACKS, because they were an awesome weapon in history. They were called the "king of battle" by the Chinese for example (the sword was the "queen of battle").
D&D grossly underrates their effectiveness and usefulness, same as it does to javelins and slings.