This article reports on an investigation into the influence stemming from school leadership as an important consideration in relation to school improvement. School readiness, based on [Schiemann, W. A. 2014. “From Talent Management to Talent Optimization.” Journal of World Business 49 (2): 281–288. doi:10.1016/j.jwb.2013.11.012]. Accountability, Capability and Engagement (ACE) leadership model, was assessed through self-reported school leader behaviours, attitudes, perceptions, and school improvement attributes. To clarify, school readiness refers to how a school principal optimises staff and other school resources to best achieve school improvement agendas. School readiness survey results and student achievement outcomes for one entire school district were analysed, indicating that school readiness did indeed impact student achievement. Findings reveal a need for school leaders to focus more clearly on overall school alignment and optimisation behaviours, and these are discussed in relation to specific leadership recommendations and how leadership can better support and encourage school improvement in terms of educational accountability.