It's been a while since I read it but it didn't seem like it was inappropriate for kids, it just had lots of thematic elements that might be over kids' heads. What's the youngest you think it's appropriate for?
What was wrong with the build-up for the "Naruto" war?
And yeah just do your part to hype up "One Piece" on Facebook.
Madara appears: "Hi there, I just wanted to say that I will put all of you under a genjutsu. I just need the 8 and 9 tails to do it. Care to hand them to me?"
Kages:"No, thanks".
Madara:"ok. Then this is a war!".
Send Naruto away with killer bee! Wait, Naruto, you're doing an S-Rank ecology mission! 4 panels later, and the war begins!
Everything, from the pacing to the foreshadowing, everything was handled in a rushed way. There just needed to be a war.
One Piece war started with the duel at Bananaro Island. Then, news on the diaries of the marines and sichi gathering at Marineford. Then, DoFlamingo says there'll be a war. Then, Luffy knows it thanks to Elder Nyon. Etc. etc.
It was handled much better in One Piece. It's my opinion, anyway.