I looked at your city and the top fellowship members. Congratulations - y'all look great!
Making "a rough estimate of goods needed ", well, it's hard to predict how many of each building will be built/upgraded, or the types / number of provinces that will be completed.
Since every fellowship is unique, your particular needs can be best ascertained via your own Trader. Production shortfalls and excess will show up there pretty quickly...so you can encourage individuals with the appropriate productions to build / upgrade in order to meet the obvious needs of your group.
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Culture vs. production is a relevant discussion - and one which seems to be a difficult hurdle for some players to leap! There comes a point where it's just not feasible to reach the 150% any more - but sometimes players will keep overbuilding culture rather th an accept that the game has reached a turning point. Often this can require your best leadership skills to convince them to keep their personal culture at a level above 100 where the fellowship can consistently put it over 125.
I mention this "culture focus" city scenario because it can have adverse effects as you try to gauge the needs of your fellowship. This individual doesn't need trade as much, since they are over-producing coins/supplies which they can use for wholesale purchases...and they've adapted to expect slower overall growth.
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If anyone needs motivation to build manufactories, suggest that they take a quick peek at the top cities. As example, in manufactory terms, I currently have 18 basic, 9 crafted and 6 magical - all upgraded to the max (with boosts over 400% and a Dwarven 25% boost). I spend their full production capacity every day. That, even though I'm completely finished with Dwarven research, so my only activities are a few upgrades and scouting. The moral of this story is that it's impossible to overstate the importance of manufactured goods in Elvenar!
One could roughly assess goods needs according to the Research tree by saying that, through Section V, every players needs "hundreds and hundreds" of each of the 9 goods. Section VI will require thousands and thousands of each.
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Province encounters will affect this need for goods, depending on the fighting skill of each player. Once a player has completed 185 provinces, the negotiating costs of each encounter range from 5k - 15k goods. Very approximately, this is 80k goods for each scouting cycle (26-30 hours). If 1/4 of these goods are magical, that represents a minimum of 120k supplies. So, comparing the cost of military training...fighting is by far the most effective way to win an advanced province, even if you virtually decimate all 5 squads in the process.
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Basic goods are fundamental, and are devoured by the game at all levels. Personally, I like a 3:2:1 ratio for T1:T2:T3 manufactories, with some flexibility through the various levels. When considering the building of a magical goods manufactory, count the rough cost of supplies:
Magical: 6 supplies per good
Crafted: 1.5 supplies per good
Basic: .4 supplies per good
Make sure you can afford to keep all the magical goods up and running
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Which brings us to Supplies. Everything hinges around how many we have, and how we spend them. As mentioned above, spending supplies on military training is cost efficient if a player fights and wins. But if both aren't happening (fighting and winning!) then do reconsider spending supplies to training a standing army. Either learn how to fight, or make the decision to have a primarily manufacturing economy. The latter means to focus spending and grid space on manufactories so that your supplies - the basic building blocks - transform into useful growth elements.
In my opinion, if a player has excess supplies (as in, often available for for wholesale purchases or for training an ever-increasing army), then it's possible that [a] workshop should be deleted and the grid space used for goods. Given the cost/time to build workshops, of course this should be approached carefully!