I'm an adoptee and I don't think my name is " my identity " , identity is far more complex than just a few letter on a pieceof paper.
The social workers who speak platitudes about identity seem to have no problems with a child's surname being changed . And half the women in this country have changed their name at some time and don't seem traumatised by it
Obviously if the child is old enough to know their name and identify with it, then it's different and you need to tread more carefully .
Lots of older children have had several names already anyway, as birth family sometimes change the child's name when a new BF comes along or a half sibling is born . One of ours had three names .
And SW can't insist on anything - it's the adopters who petition the court and choose the child's name, not SS. They won't be the ones dealing with the tears and the school refusing at 12 because your child is being bullied for being called Tyffanneee- Princess
TBH the main reason SS don't want the name changed isnt because of the child - it's because they have promised it to the birth family who they feel are their clients, not the child . And of course they , understandably , feel sorry for them . It's a sort of consolation prize .
BTW all of the above is not the PC view , so never mention it at prep groups or during the home study . SW don't like to hear the views of adoptees if they are different from theirs.