Since our Charles Ernest and his father, Charles were born in Surrey County, which is right next door to Hampshire County, I thought I'd take a look at who was from there. I did find a family and it could have been related to our Henwoods.
UK, Soldiers Died in the Great War, 1914-1919 about George Henwood
Wimbledon and residence was Wimbledon as well as enlistment.
5 Aug 1918
Rank: Rifleman in the Rifle Brigade (The Prince Consort's Own)
Battalion: 13th, number S/33622
Type of Casualty: died of wounds
1891 England Census about Bertie Henwood
54? probably 14, not 54
Father's Name: Joseph
Mother's Name: Leonssa
Where born: Surrey, England in Civil parish: Wimbledon, same for Ecclesiastical parish and town
County/Island: Surrey, England
1891 Census covering a George and a Bertie Henwood in Surrey:
Joseph Henwood, contractor
54/? more likely 14.