As an experienced analytics consultant, evaluate three distinct GA4 implementation strategies for a fictional e-commerce business selling handmade jewelry.  Each strategy should focus on different aspects: Strategy A prioritizes robust event tracking and enhanced ecommerce features for detailed sales analysis; Strategy B emphasizes user behavior analysis using custom dimensions and metrics to understand customer journeys; Strategy C focuses on integrating GA4 with other marketing tools for a holistic view of campaign performance.  For each strategy, outline the key steps involved, the estimated implementation time and resources required, potential challenges, and the anticipated ROI (qualitative and, where possible, quantitative estimations).  Finally, compare the three strategies, highlighting their strengths and weaknesses, and recommend the most effective strategy for this specific business, justifying your choice with concrete data-driven reasoning. The output should be structured as a formal report with clear headings and subheadings for each strategy and a final recommendation section.