Yes, yes I'm Chaekey biased 

but if you actually look, they're really similar :

1. They both love fashion

2. They don't like anything ordinary

3. They didn't live in Korea for too long

4. They both have alter ego's (Key with his "Diva" and C.L with her "Baddass")

5. They both are like mom's who take care of their group

6. They both love kids and spend the most time with them

7. They both rap

8. They both sing

9. They both dance

10. Their names differ from their actual names in their group