meethi mukta are distinct in character and not exactly like iccha tapasya. they have some qualities of their parents. they have their independent identity.
mukta has some qualities of iccha. she was shown sensible and sacrificing. but it doesnt mean she's exactly like iccha. iccha sacrificed her love knowing that tappu deliberately snatched veer from her only for the reason that she didnt wnat iccha to marry a ric hnadsome guy. but still iccha didnt complain. but mukta on the other hand was heartbroken.
that way she's like tapasya. she mized alochol in meethi's drink and got her arrsted by police. she also sent those provoking messages to meethi and provoked her abt her dad. so her grey shades are like tapasya. but mukta is not as evil as tappu used to be. she's good by heart.
meethi is not exactly like iccha. iccha was righteous kind gentle very pure by heart. as sami says, she's a diluted form of iccha. meethi is good by heart. she doesnt think evil about others. but she is impatient and slightly immature like tappu.
iccha saved several lives. tappu twice, vansh, veer, daddaji, girl near temple, mukta twice, yuvi once(bike scene). she has revived lives of orphan children. no one can match iccha's goodness neither mukta nor meethi.
tappu committed crimes like abeting suicide of vansh, hiring her bf to kill iccha, using her bf for her own selfish reason, faking her pregnency etc. neither meethi nor mukta are as evil as tappu used to be.
iccha-tappu were 2 extremes where you could easily argue in favour of one person i.e. iccha.
but in meethi-mukta case, both were wrong at different times and both are good by heart.