You can replace Kiril with Triton
But Kiril is strong now, it’ll take me a while to move Triton there and would Triton be better than Grimm or you say it cuz of the healing boost.
Easy said than it is done 
i have many 4* troops for all colors except blue. And i am playing almost from the game start and spent money on troops. In my clan several teammates have the same situation with other colors.