I think it's most common for Nichiren-shū temples (and Nichiren-shū followers) to have a statue of Nichiren together with the gohonzon as their main image. However, there are also temples, that have a statue of Tahō Nyorai and Shaka Norai together with the gohonzon as you can see here
*. Sometimes this group is accompanied by statues of Daikoku-ten and Kishimojin (see here
). As you probably know, Nichiren-shōshū and Sōka Gakkai do not have any statues. There are other Nichiren traditions like the Risshō Kōseikai, that use a standing statue of Shakya Nyorai as main image (see here
). I've seen a similar statue of Shaka Nyorai on Mount Hiei, so I guess they just used the iconography already common in Tendai.
*This is some kind of statuary representation of the gohonzon: The Daimoku situated between Tahō Nyorai and Shaka Norai flanked by Monju Bosatsu, Fugen Bosatsu, Fudō Myō-ō and Aizen Myō-ō, surrounded by the four leaders of the Bodhisattvas of the Earth, who in turn are surrounded by the Four Heavenly Kings. A statue of Nichiren Shōnin is at the front.