A plurality of rows of locking dogs are provided with housing flexibility between rows to allow them to share a shear loading while leaving enough structural integrity in the housing to define the windows through which the dogs emerge. The dogs can also have extensions with a surface that grippingly engages the housing adjacent the window on extension of the dogs such that loads can transfer from the housing into the extension and into the profile in which the dog is disposed rather than passing the shear stress through the window edge into the dog that is in the profile. The dog configuration can also share the load on multiple contact surfaces of the housing to reduce stress at each contact location.