Yeah I spammed the shit out of dust storm fidget and dodge to beat those two after I was killed by the single giant.... I guess that learning experience helped me. You had me on edge there when you were fighting both of them since you so easily handled the 1st one.
You seemed to figure it out pretty fast, but the bomb fruit give you a pretty generous distance to move them with dust storm.. I did what you did as well trying to move with them every foot... they can be off screen to guide them.... but not so to actually pluck them. You'll find a bunch of neat puzzles with them later... generally, if they have a timer you'll need them to blow up an easily accessible wall... if they don't have a timer right off the bat they are for a puzzle or a guide in the dark... as you saw they are pretty effective weapons too when enemies are close by.