Hmm i was just wondering.. the main thing is to test how brd song will affect the food you eat right? that mean that the only variant should be the brd song. So supposedly u want to try double attack song, attack + march song , attack + acc song.
Basically you get a party with two ninja in it and a bard. Firstly there is no need for a ninja control. Our main aim is to see which will be more efficient.. eating meat or sushi will definitely be better than not eating anything (even if it is a meager different). Secondly the two ninja must not be the first provoker Thirdly, the other DD must have constant output and also cancel their song for all three fight.
This experiment should be conducted three times. For the first time, the bard will sing double attack song. For the second experiment, the bard will sing attack + march song. For the third experiment, the bard will sing attack + accuracy song. Have a parser for each experiment. And the result will be obvious.
The main reason was doing this three different set of song because this 3 set of songs is the most common used by bards. The rest of the melee beside the two ninjas have to CANCEL out their song. It is to make sure that their damage output is CONSTANT.
The time for each experiment must be exactly the same (e.g 1hr for each experiment) and it will be best if it is the exact party. This is necessary to make sure that you are able to compare the result from the experiment one, two and three. For e.g let presume that it is a burn party with non-stop fighting. So within a 1hr time frame, the total damage output will be like 90k giving a SE of 1k (presume). So presumably experiment 1 (double attack song) , Meat nin score a 10k damage and sushi ninja score a 20k damage with total damage of 120k. Than experiment 3 ( attack + acc song) , meat ninja score a 15k damage and sushi did a 5k damage with a total damage of 110k. but utimately we can see that double attack song + sushi ninja will give the best result. (Since the two ninja in experiment three is doing less output than the experiment one ninja.)
Personally I will agree with having same merit and gear if your main aim is to test the efficency of the songs with food. But if you are out to test how your gear/merit/food combo can affect the song, I do not see the need to keep it constant.
Hope i planned it out correct. Correct me if I have some error in it.