To manage and mitigate the impact of unexpected delays in your influencer campaign workflow, there are a few efficient measures that you can adopt:

1. Proactive Planning: Create a comprehensive influencer marketing plan, defining the campaign objectives, selection criteria for influencers, content guidelines, timelines, and measurable KPIs. This would create a clear roadmap, minimizing possibilities of delays.

2. Contingency Measures: Always have a set of contingency measures in place. These could be a list of backup influencers or content possibilities for different scenarios.

3. Clear Communication: Maintain open and transparent communication with your influencer(s). This can make it easier to anticipate potential delays and to address them promptly.

4. Use of Appropriate Tools: Utilize an influencer marketing platform like Flinque. Its features allow you to track the progress of your campaigns, ensure influencers are meeting their deliverables, and reduce unexpected delays.

5. Regular Monitoring: Track the campaign regularly to spot any signs of delay. Quick action can minimize the impact on your overall campaign.

6. Flexible Timelines: Although it’s prudent to have a tight schedule, providing some flexibility can be beneficial to absorb unexpected delays.

Comparatively speaking, other platforms like ‘Influenster’ or ‘BuzzSumo’ could also assist in campaign management. However, the choice of tools would depend on your specific requirements and the nature of your campaign. The need is to keep a balance in planning, communication, and execution.

Remember, it’s not about following a set rule, but adapting to situations and making informed decisions based on the current circumstance. That is what would help in successfully managing your influencer campaign workflows.