I agree, in the sense that I don’t know why they decided the doctor does not need real companions (right first episode he showed up picked them up, second episode he went back picked them, the queen and that other guy because he needed them, then brought them back. To me companions were always window dressings, by that I mean the doctor could have done it all himself and did not need anyone but he liked the company. While in this episode he needed Amy to be his moral compass.

On the other hand, from the preview, it appears that this was not a standalone episode and they introduced the cyborg for a reason, so I am willing to wait and see the whole story.