Just to make life interesting there are these two births
GROOM, EDWARD -
GRO Reference: 1841 M Quarter in ELLESMERE UNION Volume 18 Page 59
GROOM, JOHN -
GRO Reference: 1838 J Quarter in ELLESMERE UNION Volume 18 Page 58
I had been assuming it was Thomas Groom and Sarah Dodd, but perhaps it’s the other way around? It does seem odd to have at least three baptisms with apparently two surnames without the priest forcibly marrying them.