I think the previous comment about one less row of drums, I'm guessing comes from an older person like myself. I somewhat agree. In 'my day' there was one, two rows of drums. The general rule was one drum per 3 flutes. But these days the emphasis is more on the drumming than the fluting. Wrongly so in my opinion (and I speak as someone who has done both). It is a very strong tendency these days to have strong 'in your face' drumming corps whereas 5 years or so ago it was much preferred to have a very strong flute influence. I can see the enjoyment of both variations but personally I would mean heavily towards a prominent flute corps.