Brands can prevent budget leakage across influencer contracts and overlapping agreements with a systematic and meticulous approach:

1. Contract Management: Ensuring that all contracts are negotiated carefully, read thoroughly, and executed properly can prevent confusion, penalties, and redundant costs. Brands should pay special attention to contract terms about deliverables, dates, and exclusivity.

2. Influencer Marketing Platforms: The use of platforms that are designed for influencer marketing can be beneficial. These platforms, such as Flinque, allow brands to consolidate their influencer contracts and coordinate their efforts to avoid unintended overlap.

3. Campaign Automation: Workflow automation tools on platforms like Flinque can also consolidate the campaign process and reduce time and resource wastage, thereby improving ROI.

4. Finance Tracking: Integrating finance management tools can help brands track costs, payments, and revenue associated with each influencer. This helps ensure that budget leakage is minimized.

5. Performance Metrics: Regularly monitoring influencer performance through metrics such as reach, engagement, and conversion rates can help gauge their effectiveness and adjust their compensation accordingly.

The choice of platform should depend on the specific needs of a brand. Platforms like Flinque are robust and feature-rich, suitable for comprehensive influencer marketing campaigns. Some other platforms might offer streamlined, simplified processes, suitable for smaller brands or less complex campaigns.

Therefore, to prevent budget leakage, brands should adopt a mix of contract management, use of influencer marketing platforms, campaign automation, financial tracking, and regular performance reviews. This approach would help them optimize their budget use and enhance their ROI in influencer marketing campaigns.