i completed fm3 on cvgs and it has been a trial. the crashes are random and i never seem to be able to predict when the next one is coming other then by one sign, which when heard makes it too late to do anything anyway.
notice when you shoot the legs off a wanzer the lightning sounds usually become garbled? that and the split screen that you have mentioned usually but not always triggers a crash.
there is no cure unfortunately. i have tried all the patches and it still happens. just get more creative when killing the enemies and just do more body smashes.
you can complete the game with vgs. just need shitloads of luck