Hello there,
The area between the villages, Corsley, Chapmanslade, Warminster & Bishopstrow (Wiltshire) and Frome (Somerset) is very small, probably no more than 10 miles. The village of Chapmanslade lies on the Wiltshire/Somerset border, so yes, in answer to your question, it could be feasible that someone born in the village of Chapmanslade could state they were from the nearest town, maybe Frome (Somerset).
I found the burial for James Fix aged 41 in Chapmanslade, Wiltshire on 5th January 1827, so a Fix family were definately in Chapmanslade at that time. Looking at James as a possible step-father, I came across this family, which may be a strong possiblity for your Fix family as the village of Corsley is very close to the village of Chapmanslade in fact, you can walk between the two villages quite easily!
James and Sarah Fix - Corsley, Wiltshire
Children ( all baptised Corsley, Wiltshire)
Robert Fix 4 July 1810
Benjamin Fix 19 June 1808
Samuel Fix 15 Feb 1807
(baptised Bishopstrow, Wiltshire)
Anne 28 Oct 1804
There is a marriage between Sarah Steven and James Fix 12 June 1804, Bishopstrow, Wiltshire, which would tie in with the birth of their first child in Bishopstrow, Anne .
Hoping this is the right family,
Kind regards
Angie