Whats the point of the 40 neckties?

2x20 = 6x attack
1x40 = 5x attack

Same cost, but splitting gives me 1xfree attack I mean

1x10 = 1x attack
1x20 = 3x attack

All in all the 20 ties is the 'value' option - and the 1x the finisher, basically use 20s until within 10 range?