To persuade startup leaders to dedicate time and resources towards building a strong culture, you can draw on the insights provided by Joel Peterson and Ed Batista. Here are some recommendations based on their perspectives:

1. Highlight the Inevitability of Culture: Emphasize that culture is not an optional aspect of a business; it is always present. As Joel Peterson argued, every organization has a culture, whether deliberately cultivated or not. Stress the importance of choosing to influence it rather than letting it form inadvertently. Remind leaders that neglecting culture can lead to an environment that evolves without guidance, potentially in counterproductive ways.

2. Connect Culture to Performance: Explain that culture is not just about creating a nice environment; it significantly affects performance. Ed Batista notes that startups are complex human systems where culture, informal norms, and formal practices determine how people interact. A well-thought-out culture supports efficient communication and effective feedback, which are critical for survival and learning in the fast-paced startup world.

3. Use Metaphors to Illustrate the Point: Batista uses metaphors like "video-gaming vs. ditch-digging" and "rowing vs. rafting" to describe the dynamic nature of startups. Explain that just as the right strategy is needed for different stages of a game or a type of watercourse, the right cultural elements are necessary for different growth stages of a startup.

4. Show the Long-Term Benefits: Discuss the transition from a startup to a larger, more established company. Point out that the initial informal and fluid culture that suits early "pirate" stages must evolve to accommodate the structure and systems required for scaling. Emphasize that investing in culture early on makes this transition smoother.

5. Address the Leadership Role in Culture: Leaders are levers in startups; their behavior and values are magnified. Stress that startup leaders have a unique opportunity to shape culture directly through their actions and decisions. The personal leverage they have can be used to instill a positive culture that aligns with the company's vision and values.

6. Focus on the Cost of Inaction: Caution that failing to address culture proactively can lead to issues that are much more challenging and expensive to resolve later. Culture problems can manifest in poor team dynamics, inefficient operations, and ultimately, in business failure.

7. Provide Practical Steps: Offer actionable advice on building culture, such as setting aside time for regular reflection on company values, implementing team rituals that reinforce desired behaviors, and ensuring open channels for feedback and communication.

8. Emphasize the Competitive Advantage: A strong, positive culture can be a significant competitive advantage, attracting and retaining top talent, fostering innovation, and enhancing brand reputation.

By using these points, you can make a compelling case to startup leaders that investing in culture is not just a luxury for when they have more time or resources—it's a strategic imperative that underpins the success and sustainability of their business.