“God may have had other vehicles for other peoples.”
No, there were 8 people on the ark, and only 8 souls were saved from the flood, so there couldn’t have been other vessels:
“18 For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh, but quickened by the Spirit:
19 By which also he went and preached unto the spirits in prison;
20 Which sometime were disobedient, when once the longsuffering of God waited in the days of Noah, while the ark was a preparing, wherein few, that is, eight souls were saved by water.” 1 Peter 3:18-20
So Shem was white? Ham was black? Japeth was Oriental? All this in 2350BC? How do you explain Chinese history which goes back before 2350BC?
20 Which sometime were disobedient, when once the longsuffering of God waited in the days of Noah, while the ark was a preparing, wherein few, that is, eight souls were saved by water.” 1 Peter 3:18-20
The purpose of the flood was to kill the hybrids, the progeny of the fallen angels and the daughters of Adam. God didn't have to kill all of the blacks, the orientals, or anyone else, Satan wasn't targeting them, Satan was using the fallen angels targeting Adam's family to stop Jesus from being born. Eight Adamic souls were saved, the rest of Adam's family were not perfect in their generations, they had mixed with the fallen angels. The bible is the story of Adam's family and those in contact with them.
Since the crucifixion, all one needs is to believe in Christ and they become part of Adam's family as God's promise to Abraham becomes fulfilled.