The Senju, clan of a thousand techniques, probably possessed a large arsenal of techniques and the likes that made each individual member particiularly versatile, especially since the clan itself held such diverse groups. After fighting the Uchiha for so long, yeah, they probably avoided eye contact, and instead focused on fighting their feet.
Mind you, mangekyou sharingan, especially during this timeframe, was rather limited in numbers, so most Uchiha were using just the regular sharingan. The regular sharingan is by few means OP, so it makes sense that the Senju could take on the Uchiha. Harishima taking on Madara and Tobirama taking on Izuna... Well, that's a bit of an interesting story, as Tobi used kenjutsu to severly injure Izuna, and no doubt Hari used wood release.
Senju vs Uchiha, I can see why Uchiha had issues. Madara and Izuna... No idea why they were having so many issues fighting Hari and Tobi.