Konoha had suffered many victims since the start of the war. Iwa was superior in any aspect. Be it in terms of mentality, combat experience, aggressivety, motivation, Iwa was above.
This came primarily because of the five years of development time they got. It also came because of the way Iwa groomed their shinobi. The shinobi of Iwa were strong minded, did not whine, faced any adversity, some even committed suicide attacks.
Hearing all of this instilled fear into the shinobi of Konoha before they even met with the enemy. They had already lost the battle psychologicaly, it became then easy to take the upperhand on them.
Also, Konoha had to send fresh meat to the two battlefields. Young teens and kids who freshly graduated from the academy had to go against the veteran Iwa shinobi who had fought and survived in the Warring States Period.
Now, how come those veteran could still come back after being wounded in battle? Because of the healing outposts! This gave Iwa such an advantage in the war.
"Elder brother! If only you knew....The Land of Grass is like hell on earth. I saw those of the Fuma clan, they were gravely wounded. Their guts spilled out, nobody could do anything for them....we could only watch at their agonizing faces." Tobirama couldn't forget this, it was inked in his mind.
He was standing in Hashirama's room, trying to persuade him of stopping the war. Konoha had already lost so much men in so few days.
"From everything we could've gather, we know for a fact that Iwa was established before any of us. Their tactics and organization are far superior to ours." Hashirama sat on his bed.
"That's why I'm telling you to send Iwa a meeting request, elder brother! Those of Suna are just incapable and its like they don't exist. With them as our allies, it's like we fight alone against Iwa and Kumo. This is a losing war, elder brother....no matter how you look at it." Tobirama was sweating, he wanted the war to end.
"Tobirama, let your brother rest. You always want to meddle in his bussines and to tell him what to do. Don't forget that he is the Hokage." Tobirama looked intently at Mito.
"Stay out of it! it has nothing to do with you, woman. I'm talking about Konoha's future and you don't have anything to do with Konoha." Hashirama didn't appreciate what he heard.
"Enough, Tobirama! Mito is my wife now, she has everything to do with Konoha. It seems you don't know about the Uzumaki clan lending us their strength against Kumo." Tobirama looked down, he didn't dare to look into Hashirama's eyes.
"Whatever, It's not like you're going to listen to me. You always listened to the wicked Madara and now your listening to this woman who has only being in your life just recently. When will you listen to me, your brother!?" Tobirama walked to the door and stopped in front of it.
"The only thing you had to do was to take care of Madara like you should've, you had to listen to Kentaro. Now, the young ones are suffering from your poor decision. It's never late to take a few steps back, send a meeting request to Iwa." Tobirama waited for Hashirama's answer, his back turned to him.
"You don't understand, Tobirama. Kentaro lied about being sneek attacked, it was one of his plan to turn me against Madara. He is the bane of peace-"
"The bane of peace? Tch...you're easily influenced, look at how Madara put in your head. Do you really think that Kentaro would use such pathetic tricks? He's so powerful that he could take on both of you....he even killed the bastard." Tobirama opened the door, left and shut it down.
"Tobirama! Come back here, we're not done talking!" Tobirama walked through the corridor angrily, he had enough. He had no time to waste talking with Hashirama, he had to return to The Land of Grass.
"Tobirama, are you going back there?" Tobirama's angry face returned to normal whe he heard this soft voice. A slightly blind woman stood not far from him.
"Naoki, elder brother....I don't know what's going on in his mind. I'm upset, but I cannot let it drag me down. I must return to The Land of Grass, hopefully this war will end soon enough." Naoki walked near Tobirama and shyly hugged him.
".....T-Tobirama, return safely. I'll await for your arrival. As for Lord Hokage, he'll eventually realise that this war is futile. Don't kill too many people, try to knock them down o-or something...." Tobirama couldn't help but slightly blush.
"Tobirama! Let's go. We heard that the Amburame clan has entered deep into Iwa's controlled area. They'll need our help." Tobirama nodded, he gently pushed Naoki aside.
"Naoki, I will come back." Tobirama walked out of the Hokage residence and joined the others Senju. It was time for them to return to the battlefield.
Tobirama and the Senju prepared their armors, their weapons and especially their minds. It was now common knowledge to know that The Land of Grass was a hell.
They knew that many among them would fall into booby traps, that they would witness horrible sights. No matter how strong, no matter the training, nobody could be prepared to face the savagery of the shinobi of Iwa.
"I know that Tobirama is right, but there is hope of avenging Madara. I'm sure of it, Kentaro is not an immortal. He bleeds, he has emotions, I know of a way to win the war. We must take him down. What does Iwa amount to without him?....We could attempt an assassination or....no, I can't do that...."
"Hurting his family? Killing his wife? Poisening someone who is close to him? Why can't you do that? For Konoha to be able to create peace, Kentaro and his rule over Iwa must end!" Mito was like a snake, she pushed Hashirama to hurt Kentaro's family.
"I won't do it, Mito. Even if he is our enemy, we can't be this cruel. An assassination attempt is what we need, I'll send competent men to complete this task." Hashirama knew that it was bound to fail, but it didn't cost nothing to try.
Tobirama led the Senju out of Konoha to the aid of the Amburame clan against all potential enemies. Unbeknownst to the Kamizuru clan, they would face two prominent clans sooner or later.