Don't let a greedy dragon guard your treasure. Hitting the problem straight on will be more effective than letting it slide and worsen. To solve a problem, people need to work together effectively and efficiently. If people are not doing their job, replace them.
Periodic reviews are absolutely essential.
Acknowledge the efforts made and celebrate the successes. If some people do not fit in the assigned roles and tasks, some shifting may be needed. Examine the qualities that led to their selection. Check to ensure that the assigned group or person can do the task without bias. They may be more comfortable and effective if they are placed in another role that more closely fits their skills and abilities.