Over 20 years after introducing and popularizing agile software development methods, those methods have proven effective in delivering projects that meet agile assumptions. Those assumptions require that projects be small and simple in scope and utilize small, colocated teams. Given this success, many agile advocates argue that agile should replace plan-driven methods in most or all project contexts, including those projects that deviate significantly from agile assumptions. However, today's reality is that a diversity of agile, plan-driven, and hybrid approaches continue to be widely used, with many individual organizations using multiple approaches across different projects. Furthermore, while agile advocates argue that the primary barrier to agile adoption is the inertia of traditional organizational cultures, there are, in fact, many rational motivations for utilizing plan-driven and hybrid methods based on individual project characteristics. For information systems students, this creates confusion in two ways: 1) understanding that there is no single best way to develop software in all circumstances but, rather, teams should choose an optimal project approach based on project characteristics, and 2) unpacking and analyzing the wide range of project characteristics -- including multiple dimensions in functional requirements, non-functional requirements (NFRs), and team characteristics -- that impact that choice. This paper addresses both sources of confusion by utilizing case studies from 22 interviews of enterprise software development leaders. The paper analyzes each case utilizing a "home grounds" model that graphically portrays key project characteristics and their impact on the optimal choice of software development project approach.