if i was to say, out of the blue, in 2008, my reason why many amiga games of 20 to 15 years ago, had a poor scroll, i would say that's the fact that what you see on screen, the visual aspect in a good amiga game is built through routes and tricks a graphic designer don't understand easily.
of course, that could have been different then, i know nothing about it. i can only report my difficulty to understand parallaxes, fixed and non fixed palettes, copperlist, lines etc: so either a coder is also a graphician and he knows what he is doing (the more you go back, the easier that could happen: CBM64 etc) or a coder has a graphician learned in amiga display.
even if i tryed to help on Annihilation and the EoB aga and so i read the discussions involved, only thing i can see, for instance, in a game like SotB, is count on my fingers the levels of parallaxes, and wrap my mind around the concept that there is bound to be a transparent colour!
short of that you need to stick to the more basic and heavier on the memory ways to render a moving scene.