However, the best groups and the best arrow flight are not always synonymous. Therefore, group tuning may provide slightly better grouping for your broadhead tipped arrow, but not necessarily the best arrow flight. Therefore, the arrow will not deliver it's energy as efficiently as it would have it were tuned to shoot perfect holes.
Best groups and best arrow flight are not always synonymous. The obverse is also true. Best arrow flight and best accuracy are not always synonymous. I'd be very happy to sacrifice a tiny bit of energy transfer to know that the arrow is going to hit where I aim it, rather than a few inches off. Accuracy first, arrow flight second.
Naturally the goal is to have both, perfect accuracy and perfect arrow flight. Problem is, it takes a perfect archer behind the string to achieve either.