Dance for me can only be played by Eight Ball during his activation. The way I see it, he plays the tactic, checks range 1-2 calculated from his position to the two intended targets. If both are in range, he can swap the position of both targets.
The theorie of my opponent is, that you check if two targets have a range between each other of 1-2. If yes, you can switch their position.
Third option, first target needs to be in range 1-2 from Eight Ball, second target can be 1-2 from the first target.
Of course I think my theories is correct, but would like some feedback :-) Since David is quite frequently here, even from a designer, great.