Just a comparative phrase. Many of the parts and systems on the Santorin are the same as the SM, which is bigger and heavier. In comparison to many production boats Amel made things to last, so they were well engineered. As an example the gearbox on the Genoa is furling a smaller headsail than the SM, so less generally less strain on the working parts. Similarly the C Drive being pushed by a 50 HP non turbo Perkins compared to a much more powerful turbo Volvo on the SM.
So 'over engineered' was definitely not a criticism, more of a bonus for Santorin owners.
Ocean Hobo SN96