HA primary unit selection criteria - Active-passive

Dear all,

I was reading fortigate article related to active-passive mode for primary unite selection criteria.

1. Monitored interfaces - unite with fewest failed monitored interface.
2. uptime - unite with highest HA uptime becomes primary
3. priority - highest
4. serial no - highest

If override is disabled.

Now the question is that - based on the highest as attached snapshot device will become primary if cluster uptime is higher. but  if cluster uptime is less than 300 seconds will not become primary.

Thanks in adavnced.