RNG uses Ranged WS for their TP, ridill just works like kraken for them (with slower TP gain but higher DPS), so as far as the utilization of ridill as a TP gaining weapon, they're not that much behind WAR or DRK.
That and since the recent ranged attack patch, meleeing for TP along with shooting is more than viable, so RNG can benefit a good amount from ridill too...more than "just a toy" anyway
All things considered, you can say that Ridill is just a meriting toy for WAR, because that's what it will be used 90% of the time anyway (granted that might be caused by the revamp your merit to accomodate ridill clause, but still...)