ok hang on... the idea of Marcus's last name being davenport even before bionic showdown got to me.
In i am frankie, James Peters creates Andrew, but he gives him the last name LaPierre, distancing himself from him. He barely treats him like a son, just an android with a mission.
Douglas, on the other hand, treats Marcus like a son. He's not the best dad, but there are elements of their relationship that are reminiscent of a normal father and son ("yes dad, I'll take out the trash..."). There's certainly parts of it (like Marcus's charging station looking like a cage, and Douglas thinking he was dead forever when he was crushed, and Douglas saying Marcus won't make it to his 16th birthday) that show the aspects of their relationship that are more "creator and creation" instead, but I think it's fascinating how, despite both being programmed by their creators for specific missions, Marcus is more bonded with his creator than Andrew was (though it still wasn't perfect)
Peters went as far as choosing a different last name for Andrew so he couldn't be traced back to him (also I just realized his name may start with an A bc its the first android he's built, much like how Sigourney named hers in alphabetical order), while Marcus's name broke Douglas's alphabetical naming streak for his other kids (ABCD... Marcus), both distancing himself from Adam, Bree and Chase, and allowing Marcus to almost be his own person while still identifying him as part of Douglas's family. Marcus's name allows him to be more than an experiment (Subjects A, B, and C, and probably also D) while that's all Andrew was to Peters.