So out of this discussion we got a nerf to logistics, but nothing else. I still think this is an issue that could use addressing. I'll restate my opinion for discussion's sake:
Here is my proposed changes to the archers/skirmishers:
Barrage side is the same.
Accuracy is changed to Hardened. Each level gives +10% RCS and +15% CS." Hardened 3 could offer medic 3 or march, but I don't think it needs to.
Here is my proposed changes to siege units:
Barrage changed from : "+5% RCS, +15% against wounded." to "5% RCS, +5 splash damage to adjacent hostile units." and logistics replaced with "+50% RCS to full health units." to avoid too much splash damage.
I feel that these changes will not only differentiate siege and archers, offer more choice, and more fun, but also improve the AI. (as I cringe whenever I see an AI's archers go accuracy.)
Lastly move supply to be behind level 1 coastal raider on melee ships.