perhaps increase the value of their starting province, and maybe add a mine or two to their startup buildings?

try adding these lines in the starpos file for them,

in the section
//Region Goods Available
add
SetTradableGoods:: ID_ARAGON SILK SPICES GEMS
SetResources:: ID_ARAGON COPPER GOLD IRON

in the section
//Region Attributes
try increasing the value in this line
SetAttributes:: ID_ARAGON
(set the income to what you think is a definate improvement)

in the section
//Buildings
add
MakeBuilding:: ID_ARAGON Merchant
MakeBuilding:: ID_ARAGON Improved_farmland
MakeBuilding:: ID_ARAGON Copper_Mine
MakeBuilding:: ID_ARAGON Gold_Mine

WARNING
dont cut and paste these lines, they are not tabbed,
so if you do cut and paste use tab and delete spaces to get them to behave.
(make them look like the other lines near them, but always use tabs for spacing and not spaces.)