Simply because a lot of programmers failed to write programs to make use of extra hardware (and all too frequently non top-rated commercial games failed to run at 25fps lets not forget) doesnt meen that hardware was unified, it meens only that programmers where lazy or shortsighted.
It means nothing of the sort - in fact it means the opposite, as we've gone over before. Programmers put effort into making the most popular model (A500 with 1/2 meg expansion) fly, spending their time getting the snazziest effects by hitting the metal, because that's the way you survive in a competitive market. It's not lazy to expend the majority of your energy where it will reap the greatest rewards. (Unlike Commodore who, knowing that games programmers had been hitting the metal on their games oriented computer, went right ahead and released incompatible revisions anyway.)
The 1/2 Meg expansion sure made a difference to speed though - I remember Lemmings didn't slow down when things got busy once I'd upgraded my machine (technically I suppose that's a case of the machine slowing down less rather than speeding up, but as far as the user is concerned the computer is "faster" as a result).