Agree. In addition, from an internal risk management perspective, a forex broker need only be concerned with the NET exposure, longs less shorts, per currency pair, across their client-held positions. That net exposure does not turn on a dime, but normally over many hours or days, as can be seen, for instance, from FXCM's weekly published exposures for their client base.
Taking this a step further, due to generally stable intermarket correlations, the broker should be able to control their risk cost-effectively via a relatively small number of hedging trades, in the majors only, with their liquidity providers each day.