You can script this, the easiest way would be to create a Server Action based script (so you can run it directly).

accounting_menu = env["ir.ui.menu"].search([("name", "=", "Accounting"), ("parent_id", "=", False)])
top_level_menus = env["ir.ui.menu"].search([("parent_id", "=", accounting_menu.id)])
def sort_menus(menu):
submenus = env["ir.ui.menu"].search([('name','!=',"Settings"),("parent_id", "=", menu.id)])
if submenus:
sorted_submenus = sorted(submenus, key=lambda m: m.name.lower())
for index, submenu in enumerate(sorted_submenus, start=1):
submenu['sequence'] = index * 10
sort_menus(submenu)
for menu in top_level_menus:
sort_menus(menu)This excludes the SETTINGS Menu, so it still shows as the first sub menu under CONFIGURATION - so adjust the code if you want that included in the sort.