Similarities between the Donquixote-Family (Dressrosa-arc) and the Baroque Works (Arabasta-arc)

While watching Dressrosa-arc, I started to notice some similarities with the Arabasta-arc. So I decided to share my observations with you guys.
(Note: This is not only about the similarities between the mentioned arcs, but also between the appropriate enemies of their own organisation)

•The two 'head's are/were Shichibukai and created a short 'Allinace' at Marineford with each other
•Both stories...

Similarities between the Donquixote-Family (Dressrosa-arc) and the Baroque Works (Arabasta-arc)