Quote Originally Posted by Iceflame55
Another thought might be to allow the last two troop buildings give a +1 and +2 to weapons grade. Either that, or allow EVERY unit to go get their weapons upgraded at a weaponsmith, instead of JUST the units you can build there (like the Genoese Sailors going to Tuscany!)
Unfortunately the game engine only allows you to upgrade a unit in a region that can also produce that unit, there is no way to mod this to do as you suggest, it's hardcoded.

Modding the troop producing buildings is possible but might be somewhat unbalancing, since the higher levels already allow access to superior troop types as well as providing a valour bonus at the highest level.

Kali's idea is another workable mod to do what you want, with a extention of that idea being to make the new building type - copying Blacksmith from the Viking campaign - fully buildable with prerequisites of Iron and the Metalsmiths Guild. Metalsmiths are then modded to not require Iron, but adding the prerequisite of the Blacksmith for the Master Metalsmith. You can also adjust the build times & cost for Master Metalsmith & Blacksmith so that it doesn't cost anymore or take any extra time to produce all levels of Metalsmith, perhaps setting Blacksmith at 200Fl & 2 years with Master Metalsmith at 800Fl & 8 years. Overall perhaps the most elegant solution that will definitely work.

Another idea I'm going to try when I get home is to see if it's possible to mod the Metalsmith so that Iron is only required by the Master Metalsmith. The required resource field might only allow a single value in which case it won't work, but hopefully it's like some of the other fields that allow multiple values, in which case the solution is very simple.