Now, vendor and manuf scores are not understood by players, but clearly oppose each other. Sales which increase vendor tend to decrease manuf. Production which increase manuf tend to decrease vendor.
How about make vendor and manuf uncorrelated with each other. Vendor just depend on sales, which not affect manuf. Manuf just depend on production, which not affect vendor. Big players will have advantage, but big players win anyway. At least everybody will understand system.