Sure there's much more to Aiki principles. I guess the question becomes, can a Judoka, Jujutsuka use Aiki principles in there Judo/Jujutsu? I think this is what Roy Dean has been trying to demonstrate in his approach to martials arts in general. Roy Dean knows Aikido, he is a 1st dan, but incoporates Aiki in his BJJ. I think he has a great approach to Aiki and self defense.
The secret to achieve "Ju" is through "Aiki".
Do not compare Modern Sport Judo with Aikido, because the former has lost much of its "Ju".
Instead compare Traditional Kodokan Judo (where there is a strong emphasis on "Ju") with Aikido.
You will see that the secret to achieve "Ju" is through "Aiki".