« Reply #34 on: Wednesday 07 July 21 07:10 BST (UK) »
I suggest you request one of the helpers here to post a snip of Henry John HUMPHREY's signature from his attestation document (which has been mentioned, but I cannot see- or I would do it).
I am pretty sure the signature on the 1911 is James GLEN's, own hand not Sophia's.
A comparison of the two sets of writing may help. There are some experienced "eyes" here 
Sue
here it is
Berks / Oxon: Eltham, Annetts, Wiltshire (surname not county), Hawkins, Pembroke, Partridge
Dorset / Hants: Derham, Stride, Purkiss, Sibley
Yorkshire: Pottage, Carr, Blackburn, Depledge
Sussex: Goodyer, Christopher, Trevatt
Lanark: Scott (soldier went to Jersey CI)
Jersey: Fowler, Huelin, Scott