Wouldnt be surprised if BA was looking at Hayne's defensive capabilities more then his attack when he was considering to sign him.
If you look how we defence, we play a compressed defensive line, with wingers / centres pushing in to stop the attack -they rush up quickly trying to stop the play (it happens to often, not to be our game plan). Then they are expected move across depending on what is being thrown at us . Taka did struggle at times due to his mobility to switch from pushing in to pushing across / chasing (see cowboys try in the final).
Hayne would be perfect under this defensive structure, he is strong enough to rush up and make the one on one tackle. But also mobile enough to change direction depending on the attack.
We could be a lot stronger defensively with Hayne at centre. Exciting times!!