Each strata of a law department, from person to unit to the entire function, has its own regularities and concerns. A “lower level” won’t fully inform a “higher level.” Scientists have realized for years that an understanding of atomic interactions doesn’t encompass the larger sphere of molecules, nor does understanding molecular rules explain higher-level, complex organisms. Each rung of the hierarchy has its own properties, sometimes referred to as emergent characteristics, that depend on the former but are not defined by it nor fully elucidated by it. Components don’t explain the whole; the sum is greater than its parts.
So too, forces, incentives, and characteristics operate at the individual level in a law department, but when you “move up” to the practice group, new ones emerge. And then, multiple practice groups as part of a legal department introduce yet another set of considerations to be understood. Management concerns regarding a whole department are qualitatively different than those pertaining to a portion of it.
In the sciences this is called the problem of scale, as explained by Duncan J. Watts, Everything is Obvious: once you know the answer (Crown Business 2011) at 63. Moves up the scale present new problems and insights, emergent issues, with only partial overlap with other levels.