Why the action "Contest Trade Route" is a Standard action, not a standard/realm action ?

As realm action, this action will be contest every trade route of a specific regent where the man who contest have a holding
one action court for another one trade route
( as contest holding )

And

why not
a level of trade route which increase independendly of level of guild but the average level of guild is a maximun ( as temple/law/guild for province )
in this form, the contest not destroy the route but decrease that by 1d3 level ( as contest holding )
but for trade route continue to be lucratif, the action for rule trade route cost nothing in GB and RP except a court action....

tell me what do you thing of this ( and why )