This has nothing to do with powerscaling, its simply because the Admirals aren't build as villains.
The only exception is Aramaki.
Zoro, Sanji, Law, Kid have no business with any of them.
Only Luffy, Coby and maybe Sabo need to settle the score against Akainu/Kuzan.
Imo
Fuji will turn against the WG/Marines and he will have a rematch with Aramaki.
Akainu will fight Luffy and/or Dragon/Sabo.
Kuzan will sacrifice himself or lose to Coby.
Kizaru is hard to guess.
The only exception is Aramaki.
Zoro, Sanji, Law, Kid have no business with any of them.
Only Luffy, Coby and maybe Sabo need to settle the score against Akainu/Kuzan.
Imo
Fuji will turn against the WG/Marines and he will have a rematch with Aramaki.
Akainu will fight Luffy and/or Dragon/Sabo.
Kuzan will sacrifice himself or lose to Coby.
Kizaru is hard to guess.