A team that does not communicate becomes dysfunctional and this will not only harm your business's efficiency, but can also damage the work environment and atmosphere in general. The employees will feel the effect and the overall mood will be dampened. 

When different personality types clash they need containing. If this is not done, what seems like a minor hitch, it could easily get out of control and possibly lead to bullying. 

Fear of change can be hostile to the introduction of new systems. The restructuring an organization may lead to anxiety and procedures can be opposed.

You tried to bring notions of team building with some coaching exercises, but all you get is people marking ABSENT. 

Your employees also have a personal life: what if something is wrong with it? Illness, separation, financial crisis? All these things find their way to the work place and the result is alienation, poor functionality and even lesser profitability.

Don't let issues run your Company: bring in ways to resolve issues, build up bridges, find common ground, respect and boost solidarity.

 
Don't take care of the clients, take good care of the employees. Then the employees will take good care of the clients.