If you downscale by a factor of 2 using bandlimited resampling every time, followed by a single final shrink, you'll theoretically get identical results to a single bandlimited shrinking operation. Of course real world image resampling kernels (Lanczos, cubic, magic kernel) are very much truncated compared to the actual sinc kernel (to avoid massive ringing which looks unacceptable in images), so the results won't be mathematically perfect. And linear/area-based resampling is even less mathematically optimal, although they don't cause overshoot.