Yes, we don't want to make traders required.
Then give the "banker" the abilities of a trader by default? The abilities would stack if the banker was also a trader? This way every realm is assured the basic abilities of at least one trader.
Maybe this is unbalanced with the current level of knowledge/reports that the banker has, but provides a potential solution that would relieve the trader problem. Also makes the banker a prime target for assassins or enemy realms in general.
