The rotating bid system work very well under previous systems (until they began to interfere with it).
There is no need to go to a strict seniority system. However, the rotating system is now broken so everyone is miserable. If they would fix it so that it worked properly you would get essentially what you want in top groups and far less in bottom groups. If you are senior then you might get almost exactly what you want in top bids and some fairly good bottoms bids (due to relative seniority in your group).