Does anyone else get the feeling when they read this thread that this could be yourself, or almost anyone given a certain perspective or lens? Perhaps I'm being overly critical of my own TT progress, but the OP's original definition of this "blah. . .phlegmatic. . .lacking dynamism" person is really unclear?
I would like to ask for more specific examples of what makes someone 'blah,' other than the example of them lacking ambition and/or direction with service assignments (I mention this one because plenty of associate/full faculty in my department do their fair share of shirking or ignoring service needs).
Yes to this. The unnecessarily pejorative characterization without examples leads me to think this person is just slightly different from a group of others. For instance, one thing they seem extremely good at is knowing what the standards are, and meeting them. This is a "conscientious" personality that studies show not only live the longest but are great at tasks requiring detail. This is the person who should be your liaison with IRB and OSP, mastering the intricacies of those tasks where figuring out the to-do list and getting them done is crucial. Same with accreditation reports.
Every department needs a mix of personalities, and the group here may be bemoaning their low-enrollment status and looking for a reason - other than looking in the mirror. Or perhaps their parties aren't fun enough because said person doesn't bring enough witty banter to the table. Sooner or later, this department will suffer a crisis in which they are going to want a clear-eyed, steady "plodder" to pull them out of the fire.
The department could also spend some time thinking about how and why they were not significantly scintillating enough themselves to attract a more fiery candidate in the first place, and how to change themselves to change that next time around.
Finally, could it be that this person values balance in their life? There are many junior faculty who are trying to balance a two-body problem, children, or an elderly relative, with the demands of the tenure track. That they are conscientiously trying to meet those demands (if not living for work and soaring above) may mean they have mastered balance in their lives to a degree that others could learn from.