In agile delivery, it's important to reflect on processes and make adjustments as needed. The project lead should facilitate a discussion during the retrospective to explore different estimation methods that could improve accuracy and consistency. This is a key opportunity for the team to analyze the causes of the high variation in velocity and less-than-committed delivery, and to collaboratively find solutions that leverage the team's collective expertise.
References: This guidance is aligned with agile principles, which advocate for continuous improvement and adapting the process to work effectively for the team. The retrospective is the ideal time for such discussions, as it is a dedicated moment for reflection and planning improvements for the next sprint.