Right, silver isn’t the best example. I’d, ideally, just like another raw material. Surely, the middle ages used more than food, wood, gold, and stone to get by? How about iron, lead, or graphite/carbon? Everything wasn’t made of gold, stone, and wood.
Yeah, coin wasn’t my fav in AoE3. Admittedly, I’ve played a lot of AoE3, but it’s becoming more and more a distant memory – so nuances like ‘coin’ aren’t at the top of my mind. I remember not liking that gold and silver mines went to the same resource (coin); and the eventual plantations (coin farms) and banks weren’t fun for me (auto-coin, engage!.. after it already wasn’t even necessary to drop off gold/silver at mines). Sadly, I’m not a fan of Experience and Export either. The latter are not like tangible raw material type of things; even “coin” isn’t, which the concept of was also a downgrade to me from ‘gold’ and ‘stone.’ As well, XP auto-depositing into my account through banks, trains, and the homeland was auto-pilot mode, too. (No thanks 
)
I’m looking for something out on the map that I physically task villagers to go collect and bring to drop sites 
Sorry if I enjoy that menial aspect of AoE, but the management of that is fun for me. But management in terms of gathering and their impact on tech/bldg/units/age-ups, etc. – as well as gathering before the enemy does, protecting them for enemy invasion, and the like.
It’s not that I don’t like doing the four resources in AoE1/2; it’s more that I just wish there was at least a fifth tangible raw material that I have to manage all aspects of. Another layer of interest to the game. Instead of advancing to Castle Age in AoE2 costing, say, 800 food and 200 gold, what’s wrong with adding, say, iron to that mix somehow.
Thanks for the breakdown of all that regarding past games!