I'm going to take a cue from John Harper's Agon and use weapon type to help determine individual initiative timing in an attack round.
A rough guideline for weapon categories is: Bow > Spear > Sword > Dagger > Fist
Initiative is determined for each group in a conflict by rolling 1D6. Starting with the highest group initiative, all individuals within a group with the longest weapon type make their attack. Continue with the next lower group initiative and so on. Once all attacks are made with the longest weapon type start again with the group who rolled the highest but this time with the next shorter weapon type. Continue till everyone who can make can attack has.
This gives some mechanical benefit for having a spear, for example, without altering to-hit modifiers for weapon length, etc.
After some feedback over at the Swords & Wizardry forum:
When two groups are considered to be corps-a-corps (body to body) flip the order: Fist > Dagger > Sword > Spear > Bow