Tyler Boyd's statement is false (Yes, it is)
Grepolis doesn't work by milliseconds; it works by whichever atction was performed first. Lets say you send your Cship out on a trip that takes about 12 hours, and it's set to arrive at 12:01:27. Now, your LS nuke is closer, and only takes 3 hours to travel; you send it out, and this one is also set to arrive at 12:01:27 - if this happens, the attack that was sent first will arrive first, and the attack that was sent second will arrive second (and third, fourth, etc, etc), meaning your LS attack will hit after your Cship
The same goes for support. Your Cship is set to arrive at 12:01:27 - your support only takes 4 hours, thus is sent later than the Cship. If it is set to arrive at 12:01:27, the Cship will hit first, and the support will arrive directly afterwards.
This also applies to sniping. If your Cship takes 12 hours and lands at 12:01:27, someone that sends an attack to arrive at 12:01:27, and this is sent before your support is sent, will actually hit inbetween your Cship and your support wave; it's hard to pull off, but it's possible!
tl;dr: Grepolis doesn't work by milliseconds; it works by whichever action was sent first, arrives first.