The Accuphase isn't using them in parallel they're summing them together in an array. It is an interesting design but looks hugely complicated with inevitable long signal paths and tiny mistakes that add up compared to a minimal design.

Yes chips like the TDA1543 as used in the Chameleon can be paralleled for better resolution, but single TDA1543 is more natural in the mids and top end with the penalty of lower dynamics and 'richness' of the paralleled chips. The TDA1543 is nearer 14 bit resolution in reality, so parallel operation is an easy way to sum out the errors and get closer to 16 bit resolution, definitely more of the source material retrieved, but no free lunch as it won't have the timbre of a single chip.