Two things, going on here.
1. Village or tribal generational names account for the middle name for the boys. Likely the same with the Ko Ping brothers. If you know the father and grandfather's generational names, you may be able to track down their hometown.
https://en.wikipedia.org/wiki/Generation_name
2. Your wife is applying the same naming principle to the daughters in english. Another variation is name all the kids with the same first character; Anna, Ashley, Alfred, Alan, etc
1. Village or tribal generational names account for the middle name for the boys. Likely the same with the Ko Ping brothers. If you know the father and grandfather's generational names, you may be able to track down their hometown.
https://en.wikipedia.org/wiki/Generation_name
2. Your wife is applying the same naming principle to the daughters in english. Another variation is name all the kids with the same first character; Anna, Ashley, Alfred, Alan, etc
In my wife's family, the three sons share the same second character for their given names, as you describe above. But the three daughters share the same first character and have unique second characters, as in the example, Anna Lee, Anna Maria, Anna Cristina.