Well top parse for ANY job (yes including healers and tanks) have a dancer attached to it, because there is no way you can beat a permanent 5% buff by player skill alone.
Top parses are also meaningless to look at, as everything is done during the run to make one person shine and people takes turn being the one shining.
If what you want is optimal raid usage, giving your 5% to the highest dps is a safe bet, as his 5% would be a lot higher than the 5% of a DNC (who has one of the lowest personal dps to compensate for the highest utility).
You can maybe have a bit more optimization as some classes might benefit more from the other temporary buff and / or devilment and partnering a slightly lower dps might be better, but that's static and fight dependent.
When in doubt partner the highest dps.