there is also the giant that makes more damage if you want to do crit
Sure but why not leaving both chances for a crit there?
Here a little example(Charge RP is meant during the the sleep debuff is active):
...Sleep, Charge RP, KD with Scattershot, Super Kame , KD with Turtle Rod Hurl, Giant Kame,...
this looks better to me than:
...Sleep, Charge RP, KD with Super Kame, Giant Kame, KD with scattershot...
Besides against SKs you could use 3x KDs instead of 2x which is more useful than trying a crit on them, because of their high anticrit.
If it happens that you use a lot of CD the Turtle Rod Hurl KD can be also spammed, providing you have enough RP of course