New patches always seem to be coming out. While it is very important to apply these patches, it is also important to be aware of the patch levels on all of the systems that you are trying to manage.
Patches should initially be installed during the at Solaris Operating Environment installation. By doing this, all systems will be at the same level.
Maintenance of the patch levels should be done at regular intervals, if possible. All of the like systems (same application/function) should be done at the same time, if possible. Of course, patches should be tested and then deployed in a staging environment before being put onto production systems.
While it is not always possible, try to keep all of the systems of a like function and ...