Yes this is a common point. If there are multiple results the user need to take the lead and choose the correct one. There is nothing where calibre can make your decision. Same is for covers.
If you have, use ISBN for our search w/o anything else. Thats the way I obtain more favorable results.
If there are additional covers you can choose whatever you want or even take another cover from all source you like and place it by drag & drop in the edit metadata window.