All the newer Cave games are protected anyway. They won't work without dumps of the Internal ARM roms, which may mean having to sacrifice many PCBs to 'decapping' in order to dump the various different internal ROMs, revisions and regions.
Attempting to simulate the ARM won't help as Cave effectively use them as their 'bullet processor', which is pretty complex (I believe I read somewhere that they have a patent on it due to it's complexity and intricate details)