Policy making and the decision-making process has developed over the past decades to include more (scientific) evidence to support policy construction, such as the Cost-benefit Analysis or Environmental Impact Analysis. However, depending on the perspective of the policymaker as well as the evaluator, successful policies outcomes may be different for varying stakeholders. This can then potentially lead to conflict during the decision-making process for future policies, on which metrics were deemed successful. Through case studies, in which the advocacy coalition framework will be applied, the role of CBAs and EIAs is explored on the decision-making process for public policy. How the procedural policy tools affected advocacy coalitions’ beliefs and strategies for/against policies is analysed. The ex-ante evaluations without legislative support for incorporation for policymaking seemed to have little effect on policy- or core belief-changes of stakeholders, even when confronted with negative outcomes. With enough opportunities created by coalitions to discredit outcomes not in line with their beliefs. Furthermore, the multi-level decision-making seems to be dominated by the national level government, who hold and maintain formal authority while preventing opportunities for intervention without legislative support. Instead, procedural policy tools that have more legislative support, have more influence on the policy implementation and decision-making process. Procedural policy tools seem to be more informative and symbolic, with outcomes more used for debates without nuances rather than to explore and improve new policy options. Hence, limiting the formal role of the policy tools to explore policy alternatives. The late timing of tools’ use in the decision-making process and exclusion of regional stakeholders in the appraisals exacerbated negative experiences for regional stakeholders. Leading to increased distrust between advocacy coalitions, preventing compromises from being found while creating more conflict among stakeholders. Furthermore, procedural policy tools were very resource dependent, limiting regional actors’ ability to perform analyses due to limited resources. Making them highly dependent national governments, fuelling the distrust and conflict based on the earlier mentioned exclusion and lacking transparency. Creating information (and resource) inequalities which can be exploited during the decision-making process. Suggestions for improvement and conflict reduction are the introduction of formal third-party supervisory committees for procedural policy tools and mandatory (regional) stakeholder-inclusion and methodology’ transparency measures.