I am aware that the universally accepted style is to put an apostrophe-s at the end of the second possessor's name.
Example: Amy and Steve's car
My question is not whether that is the common rule; I know it is.
My question is whether anyone knows of a style guide, grammar, or other authority that condones writing this in the usual style of a plural possessor; that is, with an apostrophe on the end of the compound/plural owner's name:
John and Jacks' house John Merrill, Stephen Arthur, Chuck Williams, and Donald Smiths' law firm