Sadly, we can't currently only change props from techs, we can only swap in a whole unit actor. So, the best you could do is "levels" of gear, like "Basic Kit" -> "Medium Armor" -> "Heavy Panoply", which is fine and can definitely work. Then attack could increase by ranking. 

Best would be to add a poll to the thread @Baelish

For the context, please read https://gitea.wildfiregames.com/0ad/0ad/issues/8599. I want to explain why I choose 5 gatherers for small ruins. Many entities inherit from template_gaia_ruins.xml, with different amount of stone and metal. I will do a summary of them: STONE stone_statues_kushite_bird, stone_statues_kushite_lion, stone_statues_kushite_ram 200 standing_stone, stone_statues_egyptian, stone_statues_kushite, stone_statues_roman, stone_structure_small 300 stone_column_roman 400 column_doric, roman_rostrum, stone_statues_persian_lamassu, stone_structure_farmstead, stone_structure_house, stone_structure_tower 500 METAL metal_statue_discobolus, metal_statue_poseidon 400 metal_statue_apollo, metal_statue_isis, metal_statue_wolf 800   As reference a small cut of rock has 1000 of stone and 12 gatherers, so I thought that would be a good deal to set 5 gatherers for something that has around 400

may even take it a step further, custCWA chart - Sheet10.pdfomize the weapons too (not the graphics though, just the stats, length, speed etc) based on this chart, if you find it fairly accurate.

correct, and all ranking up does for you is give you a little bit more health and a little bit more melee attack or range accuarcy.