Technically the Grail was not so much "dismantled" as outright stolen.
And the people who stole it from what I have learned about them are coming across as utter morons.
Four major cases come to mind.
1. They stole the Greater Grail from Fuyuki, likely pissing off everyone else involved , while also painting an enormous bullseye on their heads by proving that the Greater Grail can be stolen and transplanted to new areas. Like that won't attract a lot of attention now that they have proven it can still work in starting up Grail Wars, despite having to rip it out of leylines and transplant it into new ones. Seriously they are just asking for trouble.
2. It's after the Third Grail War, so a certain Evil God is still likely to be inside the Greater Grail. Admittedly this may not be their fault because only the Einzbern's knew about Angra Mainyu's nature. But one could conjecture that in taking nearly sixty years to get the Greater Grail up and running they would have noticed something.
3. For some reason the Grail is summoning a total of fifteen Servants, seven "Black" with the organization who stole the Gail, Seven Red with the Clocktower, various freelancers, and Shirou Kotomine as a representative of the Church. They have compounded the errors of the three previous Grail Wars which led to no one winnnign by upping the number of Servants and having an "alliance" of seven Servants and Masters on their side. ........... Utter Fucking Stupidity, this will lead to backstabbing and likely the collapse of their own organization as it's most talented individuals try to murder each other in order to win the Grail War, as well as fight off the other Masters and Servants.
4. Yggdramillenia, the group which stole the Grail has idiots as masters. A major examples are the guy who told Siegfried "shut up unless you have to use your Noble Phantasm", ignoring the fact that Servants can resist the effects of Command Seals temporarily and the fact that he is pissing off a nigh invincible killing machine. Another example is the leader of the group, the man who fifty years prior stole the Greater Grail. He summoned the Apocrypha version of Vlad Tepes Dracula, a man well known for not tolerating any insult to his person, in Transylvania where by the nature of Servants he will be at his strongest. Keep in mind the Grail War in this setting takes place in Transylvania. One wrong move and Dracula will fucking paste the man.
Oh and they lost their sides Assassin class Servant when Loli Jack the Ripper killed the Magus who summoned her and adopted the prostitute he was living with (and planning to kill) as her Master and surrogate mother.
Well this looks like a very interesting Train Wreck in the making. I can't wait to get a full translation of the first novel.
Highlights will include Red Saber (Mordred) summoned as a Servant by a freelance shotgun wielding Necromancer, the legendary centaur Chiron (who taught Heracles and other legendary Greek Heroes) as Black Archer, and Jean D'Arc as Ruler overseeing the whole affair.
Also Black Caster is Solomon ibn Gabirol a legendary Jewish Philosopher who was a major force behind Neo Platonic theory (which espouses the use of magic) and reconciled it with Jewish mysticism. He seems quite interesting. And he looks pretty cool as well.