This is true, agreed but also sad for his personality. U_U
Senju lineage of heritance is widely spread from their ancestors, in the other words means there must be some inter clan marriage happened, but its not in Uchiha's clan problem, where they just keep uchiha blood just between themselves and therefore we already see them wiped away instantly.
It's confirmed now that Madara was stronger than Tobirama so Tobirama was scared.
Todays chapter confirms that their love growing stronger enough so they can go along with Senju and eventually the reflection of their love turns into a great power that is beyond Senju's love.
Their hatred of loosing their comrade giving them the power of EMS.
That's why Tobirama is happy that Uchiha are annihilated now. U_U