Bluntly paraphrasing and/or summarizing the responses you have gotten so far.
You will not be hanging panniers on the rack you have. You will add a supplementary rack to support the panniers of your choosing and it will be awesome. It will be quick and easy to install your pannier rack, and it won't interfere with your existing rack. To repeat, do not attempt to hang panniers from either a Nitto M12 or a Nitto M1 front rack. Those racks are specifically intended to support a very small very top load. The rack in the photograph may already be massively overloaded, if you take the load recoimmendations of Nitto seriously. Some retailers of Nitto Racks recommend loads that they pulled out of thin air, and did not come from Nitto. Please be careful. Some front rack failure modes can conspire to put the riders head on the ground, and are to be avoided.
Bill Lindsay
El Cerrito, CA