BB-8 - Partial success (in the sense that he's always there, doing whatever he can.)

Maz Kanata - Success (in of wisdom and longevity only.)

Hera Syndulla - Partial success (overall.)

Din Djarin - Technical success (he doesn't replace Boba Fett, but he's become a successful character in his own right.)

Giving partial successes a 0.5, successes a 1 and technical successes a 1 as well, that's 3/10.