When i was about to begin the siege of Rome as Brutii, the game crashed every time. If you are in the same situtation, try attacking the near SPQR army outside the city, so the other army from the city will come to aid them. This way you can kill them all. After this, the city will be under Rebel flag, but you can now begin the siege, the game is not crashing because SPQR doesnt exists anymore. I hope this helps someone. After this (and 49 other territory) GG for the "Brutal Victory" :)