There are other Luetchford offspring as well as those on the army records
Nellie/Ellen Devine also came from an army family - she's in Ashton barracks in 1891
It all seems to fit, but not sure how exactly to prove Percy is Barry. it would be interesting to see the birth certs for the Luetchford/ward children born after the second "marriage" and how Lucy describes herself on her second marriage. The entry doesn't look like that of a divorced woman, which tends to have both maiden and first married surname