Axeman line upgrades:
Bronze Age - Bronze Axeman:
60 HP, 6 damage, no armor or 1 pierce armor because RoR balance change, moves 5% faster than swordsman line.
Iron Age - Heavy Axeman
75 HP, 9 attack, no armor or 1 pierce armor because RoR balance change and moves 5% faster than swordsmen line.
Iron Age - Falxman (axeman elite upgrade only for select few civs and preferably to barbarian factions when added)
85 HP, 12 attack, no armor or 1 pierce armor because RoR balance change, +5 vs hoplite line and moves 5% faster than swordsmen line.
Short Swordsman +5 HP from 60 to 65.
If spearman will be added I would remove axeman bonus vs mounted units, which was added in RoR.
Tool Age - Spearman
40-45 HP, 4 attack, +8 vs mounted and no armor.
Bronze Age - Improved Spearman
50 HP, 5 attack, +10 vs mounted and no armor.
Iron Age - Auxilary Spearman
60 HP, 6 attack, +14 vs mounted and 1 armor.
Slinger line upgrades:
Bronze Age - Improved/Heavy Slinger
30 HP, 5-6 range, damage 3, pierce armor 2-3, is effected by melee armor upgrades and damage bonuses are same.
Iron Age - Elite Slinger
35-40 HP, 6-7 range, damage 4, pierce armor 3-4, is effected by melee armor upgrades and damage bonuses +1.
Scout line upgrades:
Bronze Age - Light Cavalry
75-80 HP, 6 attack, 1 pierce armor, +3 vs ranged units and +5-10% faster than other cavalry or as fast as horse archer. Should also have conversion resistance like chariots since some civs don’t get chariots.
Iron Age - Lancer
100 HP, 8 attack, 1 pierce armor, +4 vs ranged units and +5-10% faster than other cavalry or as fast as heavy horse archer + conversion res. As special power it could have +10 charge attack with cooldown.
Camel rider should have iron age upgrade.
Iron Age - Heavy Camel Rider
140 HP, 8 attack, 1-2 armor, attack bonuses either same or +2 vs cav and +1 vs chariot/elephant compare to regular camel rider.
Heavy Cavalry +15 HP from 150 to 165.
Iron age upgrades to some Archery range units.
Iron Age - Heavy/Royal Chariot Archer
85 HP, 7 range, 5 attack, no armor and has conversion resistance like other chariots.
Iron Age - Elite Composite Bowman/Recurve Bowman
50 HP, range 7-8 (should have higher range than mounted archers, it thats not too imbalanced), damage 6, no armor.
Ballista Tower damage from 18 to 25.
I would add Rams to Siege Workshop so we could have more diverse siege options.
Bronze Age - Battering/Light Ram
150 HP, pierce armor 20 ( Ballista Tower should be capable to destroy them so they should have 5 pierce armor less than basic ballista tower damage), damage should be better vs buildings compare to Stone Thrower or it has faster attack and better DPM.
Iron Age - Armored/Heavy Ram
185-200 HP, pierce armor 35 (it would mean that ballista can deal 5 damage per shot), damage vs buildings should be better than Catapult or it has faster attack and better DPM.
Iron Age - Siege Ram
250-300HP, pierce armor 40 (it would mean that helepolis can deal 5 damage per shot), damage vs buildings should be better than Heavy Catapult or it has faster attack and better DPM.
Perhaps there should be also ultimate Scout Ship line upgrade to some most powerful naval factions.
Iron Age - Quinquereme
225 HP, 15 damage, 7 range and no armor.
Since cavalry is suppose to counter archers perhaps cavalry should get tech, which gives them +1 pierce armor to make them more effective vs bronze and iron age range units.
Here are some my ideas, which could be in future updates in RoR. Feel free to discuss.