¶ … hypothetical situation where there are two different GS-14 ranked managers and why it is prudent for those positions to exist concurrently with a single GS-15 position on top of that. The separation between the two GS-14's is present because they have separate portfolios. However, they are both generally responsible for providing oversight and managerial direction. In answering this question, items (2)(a) and (2)(c) will be addressed. The former is how/why the duties of each unit chief and the office director are not duplicative. The latter relates to why there needs to be a GS-15 and two GS-14's instead of merging one of the GS-14's into the GS-15 position. The question and concerns being addressed in this report shall be addressed in a series of bullets that address the different dimensions and facets of the situation being assessed here. These are as follows:

Having two separate positions below the director is the way it should be. Indeed, having a single GS-15 over the two GS-14's is the right structure.

Each GS-14 will have their own portfolio and that GS-14 should report their ongoing findings and issues to the GS-15 person.

Merging one...

Each of the GS-14's is currently managing their own portfolio and it is (and should be) the role of the GS-15 to monitor the progress and performance of the two GS-14's. If one of the GS-14's was merged with the GS-15, the GS-15 would presumably continue to oversee the work of the GS-14 that is not merged as well as his/her own duties before the merge.
Keeping things efficient and streamlined is a noble thing to do and try but there is also the idea of giving too much to do to a high-level manager/director. If any single position (of any rank) is given too much oversight or power, things will be missed and/or will be rushed.

As noted by the parameters of the assignment, the existing position structure can and should be monitored and looked at, at least intermittently, to ensure that duties do not conflict or are duplicative. Indeed, if the duties of the two GS-14's are very similar and overlap a lot, perhaps they could be merged. However, if they are too different and/or merging with another position (like the GS-15/GS-14 merger mentioned earlier) would…