In the earlier parts of LOCH, mercenary warriors such as Sa Tung Teen, Pang Lin Fu, Leung Tze Yung, and Ling Tze Seung Yan were able to live it up because they were the best wulin warriors whom Jin prince Yeun Nan Hung Lit could hire to help him kill Gwok Jing and disrupt the plans of the Mongols and the Sung. Later, however, the Jin were able to recruit West Poison Au Yeung Fung (a Great) and Iron Palm Union Chief Kau Cheen Yan (a near Great) into their service, which would seem to render the other flunkies redundant (though they nevertheless managed to stay on with the Jin until Yeun Nan Hung Lit was captured and executed by the Mongols).
If you were one of those Jin flunkies, however, wouldn't you be concerned about your job security after Kau Cheen Yan and especially Au Yeung Fung joined up? Your new "colleagues" can do your job WAY better than you could ever hope to do, which is usually a very bad sign for a person's job security.
If I were in the Jin flunkies' position, I'd consider applying for work with the Mongols or the Sung after Au Yeung Fung joined up.