I'm a character analyst unfortunately and I fell in love with the show for the concept and more so for Ariya, because from the first scene itself Shaleen-Sana shared absolute sizzling chemistry, which was more so because of their characters, with Arjun being this tough super cop with a past and who is living to avenge his wife's murder, and Riya being this really bubbly, vivacious, naive yet a very strong and a intelligent girl, which made us hooked on to them, because for Arjun who doesn't seem to have any life and lives with his wife memories, he needed someone like Riya to shake up his life again in a good way :) That is main reason why I loved Ariya so much !! After Riya died, I continued watching the show and my interest was piqued when Aisha entered the show, but from the first scene between Arjun and Aisha I didn't feel any chemistry, which was again because of the characters again ! Aisha is this really brave and strong woman, who can take care of herself, and her scenes and interactions with Arjun were always more like him interacting with Shree or Chotu, as in as if she was just one of the guys, but since she is a girl, Arjun treated her with the same respect he gives every woman :) Later on I started liking Aisha scenes with Sameer, so its good to know that Sameer would be paired up with Sameer, they look good together :)
As for the new new lead coming, again for me it will depend upon the character she has, and how well she share the screen space with Arjun and the team. Haven't watched her first show, but she seems lovely enough, so I will give her a chance for sure :) But for me Ariya would always be number one jodi as far as Arjun is concerned :)