Change openssh private key order

[Mel Pilgrim]

I have rsa keys and an ed25519 keys.  They're both made available via an 
ssh-agent.  All keys are in the authorized_keys files of the servers in 
question except for a few legacy cases that only have the rsa keys due 
to lacking ed25519 support.

I want the connections to prefer the ed25519 keys over the rsa keys, but 
looking at debug output, the RSA keys are always tried first.

Is it possible to change the order of precedence for private keys?  If 
so, what option do I set?