It seems that Keymaster and I had the same idea independently.
I saw LeaTheFlameboy unaligned for at least a few days before his nation aged to 21. So I sent forces, as far as I can tell, the same tick Keymaster did. I had neglected to bounce them off another Saddle beforehand (though I tried, but did not know that going into stasis returned troops you were sending to defend), so Keymaster got there first. But still, it was an unaligned Saddle as far as I could see.
The wartick when it seems we both sent forces was after noon on the day when the nation turned 21. That same wartick, LeaTheFlameboy threw up a nominal defense force of 100 unarmed cavalry and went into stasis.