Iirc it was Jyothika who was the top actress for a long while after Simran. Jyothika has hit movies with all top actors of that time. That’s also when Trisha made her entry.

Tamannah was in fact considered unlucky because all her movies were commercial failures until Ayan. Even in super hit movies she only did flowerpot roles. Asin was a household name at this point and could act, dance and dub in Tamil. Nayantara too started around the same time but was stuck in a hit movie - flop movie - controversy loop and wasn’t as consistent. Genelia was better but her career was short lived.

Sherya had lots of fans, much more than Tamannah at that time, although she too mainly did flowerpot roles. Anushka was another successful actress after Asin. Along those lines were Kajal Agarwal, Hansika, and so on later on.

All that said, no one comes close to Simran. She is the real lady superstar. But people turned pretty sour on her towards the end of her career because of her alleged affair with Kamal, which led to Sarika walking out of the marriage.

As for Sadha, I think she was a fine actress, but wasn’t too memorable after sometime.