It is not necessary some people prefer to tie the finishing know by hand, i first started tying the whip finish by hand as well bought a whip finishing tool took some practice to get used to it but i now use that when finishing up my jigs. It really is a preference to the tier how they apply the whip finish knot.
I also make allot of the smaller jigs using 1/100th oz jigs on a #12 hook for Gill fishing as well, my favorite jig right now is the cap spider, i am finishing up my assortment of color patterns and will be posting some pics on here shortly