On Zero to Monero page 43, each key vector in the ring signed by RCTTypeFull consists of public keys for each input, followed by a public key which is the sum of output commitments minus the sum of input commitments.
MRL0005 on page 9 describes almost the same thing, except the public keys for each input are followed by the sum of public keys for those inputs plus the sum of output commitments minus the sum of input commitments.
Since Monero has implemented the Zero to Monero version and not the MRL0005 version, it has been deemed overkill to include the input public keys twice.
This is because the way that challenges (the c-value hashes) work in the MLSAG ring signature forces it to be the case that for one ring key vector, all private keys for all public keys are known.
Thus it could not be the case that the signer has knowledge of the private keys for the inputs but not also the private keys (a.k.a masks a.k.a blinding factors) corresponding to the commitments of those same inputs.