Your great grandfather Leonard Clark born 1883 in Fordingbridge, Hampshire, mother's maiden name INGS.
William CLARK and Jane INGS married in Fordingbridge in 1881.
Leonard Clark and Bessie Rolls married in Christchurch registration district in 1903, this is the district for Pokesdown.
The family lived in Paisley Road, Pokesdown, with William and his siblings Percy, Nellie, Winnifred and Alfred.
All this indicates the birth BumbleB found in Christchurch is the correct one.
For info. - confirming William Leonard's dob
Leonard Clark Age 31 Fordingbridge Hampshire
occ PainterService number 48679 Regiment Royal Garrison Artillery Year 1914
Next of kin wife Mrs Clark 2 Flat Iford Christchurch
I see FreeBMD 1903 marriage Bessie surname ROLLS
perhaps a mistake on his army record her surname looks to read Harvey
Married 5 Sep 1903 Christchurch
Bessie Harvey spinster, witnesses W B Clark & Emily Harvey
Children
Percy Herbert 4/2/1904
William Leonard 17/2/1905Nellie 26/8/1906
Winnie 12/4/1908
Alfy 22/5/1909
all above born Bournemouth
Charlie 14/5/1912 born Christchurch
Reginald 29/5/1914 (d/c shows he died 7/3/1915 age 9 months of Pneumonia & Convulsions, son of Leonard Gunner Garrison Artillery & House Painter, Bessie was present & informant
AddedI wonder if this might be Bessie Rolls on 1891 census surname Harvey, born before her mother married
Avon Road, Christchurch, Hampshire
Emma Harvey Wife deserted 1864 Laundress Knowle, Dorset
Bessie Harvey Daughter 1884 Bournemouth, Hampshire
Louisa Harvey Daughter 1887 Bournemouth, Hampshire
Hanny Harvey Daughter 1888 Bournemouth, Hampshire
Albert Harvey Son 1890 Bournemouth, Hampshire
Nellie Harvey Daughter 1891 Bournemouth, Hampshire
RG12 Piece 904 Folio 170 Page 33
Marriage Dec 1885 Christchurch
Emily ROLLS
Male name on same page
Walter Augustus HARVEY
Bessie ROLLS No mother's maiden name given on GRO indexes
1884 J Quarter in CHRISTCHURCH, HANTS Volume 02B Page 677
Nellie Louise HARVEY
mnn ROLLS 1891 J Quarter in CHRISTCHURCH, HANTS Volume 02B Page 655