Actually there is. In MM's, the question marks are strategically placed between the words, whereas here, the question marks are placed on the edges.
I'm gonna guess the FoD health bar is about 700k-900k health. I notice it goes down 1% after about 3 people unload. It has a big defense though. A full unload with both atk and spy is ~3k..ish. I once max crystalled with an account and got 7 quick unloads. That's about 18-20k damage total. It went down 6%. Others probably hit too. It's too hard to really predict unless you get nobody to hit and test the 1% yourself. Which nobody has.
I would say enough so you have above 300k spy attack. You can always alter it if youre still failing the end ones.