Thank you post: this community helped me build a great collection
Brass Birmingham's card economy teaches a specific kind of planning that carries over to other economic games. Each card in your hand is both a location and a resource. Using it for its location spends it as a resource. Using it for its connection spends its location. Understanding this dual nature is the game's entry point.
The coal and iron merchant dynamics create supply chains that require reading your opponents' needs as well as your own. Building coal when someone else needs it is both a service and leverage. The merchant tile bonus scoring in Birmingham makes the endgame geography matter in ways Lancashire's simpler scoring does not.
For players struggling with their first few games: focus on building iron and coal for yourself rather than racing to be the fastest builder. Your own supply chain security makes the game more stable. Aggressive building without resource access creates the glass cannon problem that punishes Birmingham beginners.