Have you ever thought Russell T Davis and Steven Moffet Companions were similar because I noticed they were pretty similar.
Rose Tyler and Clara Oswald
Everyone noticed that they are alike. Clara and Rose both live in the powell estate, they both had a crush on their doctors ( 10 and 11 ) but had a spicy relationship with their other ( 9 and 12 ). There are loads of small things like the way they act for example when 10 and rose get the sonic and chair 11 and clara do the same in the crimson horror. Also They have big impacts on the Doctors life and have a mystery ( Bad wolf and The Impossible Girl. )
Martha Jones and Amy Pond
So you would expect to see Amy with Donna or Rose but with Donna and Rose its only a couple things that make them similiar Rose and Amy having a great freindship with The Doctor and running away from their life to be with the Doctor.
With Donna it was only having a good freindship and being fistey but I feel like their wasn`t much similar with them for a start Amy thinks alot of herself and Donna thinks shes well useless and that does not change. But Martha and Amy are very similar first of all they get married to another companion, they are VERY BRAVE and INDERPENDENT, they also leave the Doctor to have home life and return ( series 4 for Martha and series 7 part 1 for Amy ). The other thing is they are kick ass companions for example Martha when she walked the earth, when she was on the moon in her first episode and all throughout series 3 and 4 and Amy when she was fighting the dinosaurs, when she stuck with the photo of the angle becomeing an angle and when she fought vampires.
Donna Noble and Courtney Woods
Okay first of all im sorry to Donna fans but Donna and Courtney are similar you`re proberly wanting someone better for Donna like Amy or Clara maybe Rory but even if Courtney only went on two adventures shes still a companion and the reason I think she`s Donna`s equivalent is because she didn`t think much of herself just like Donna, she was funny like Donna and she spoke her mind and was a bit of rebel like Donna. Honestly I want Courtney to come back not as a full time companion more as a part time companion like river song or Jack.
Jack Harkness and River Song
Come on who else would be Jacks equivalent they are both kick ass and they have a mystery around them ( the face of boe and melody pond ). Another thing is they come back on diffrent episodes and flirt with everyone River is the female equivalent of Jack .
Mickey Smith and Rory Willaims
Mickey and Rory start off as a bit weak and scared but as the story goes along they BOTH become braver and into hero`s. Mickey ended up breaking up with Rose and marring Martha while Rory married Amy but they divorced for a bit but got back together.