I can't believe you lost most of your time to tell what everyone else knows.
Every hardware has its flaws. And if that M92 was engineered quite right, Irem wouldn't need to revise their hardware for every game they put out. Are you telling us that a Neo wouldn't be enough to pull a Gunforce 2?
Last Resort slowdown has nothing to do with power.
Same goes with Metal Slug 2. X is basically your answer.
And yes, everyone knows that the CPS2 is more powerful than the AES/MVS. Mentioning it alone is already unnecessary. You were comparing an M92 and a Neo, not a CPS2.
And btw... the Snes can do 512 pixels x 448 pixels.