Multiple Firewalls - wanted to upgrade on same timing

Hi,

Managing multiple firewalls and has set it to have automatic patch schedule the SAME for all, following this link:

https://community.fortinet.com/t5/FortiGate/Technical-Tip-Automatic-Patch-Upgrades/ta-p/272899

However, I noticed that during actual patch schedule, the said firewalls are not updating the same time. Some will have its automatic patch schedule the day after or 3 days after. Is it possible to sync them all?

What are being considered in the automatic patch schedule aside from the SAME config for each firewall?

Thank you!