Even merely looking at both one knows, let alone chanting to both.
You can place Nichiren's Gohonzon over the SGI Gohonzon with some paper clips preferably some small red ones that blend in with the red back ground until you find a suitable backing - the sooner the better you get started and roll up the SGI Gohonzon and even remove it from your property for a clean break and a new start for a new improved life
There are wonderful acrylic frames you can buy and the stores will mount the Gohonzon for you so you don't need to keep the SGI scroll for another minute.
Dull or bright, the Worlds of Anger, Avarice, Stupidity, and Anger, or the Worlds of Learning, Self Absorption, Bodhisattva, and Buddha. Your choice.