I suspect once you get comfy with the rhythm then you’ll find it won’t matter to you as much what kind of floggers you use. When I was first trying to learn it, it felt like the least little thing could throw me off. Once it was down pat, it got so I could probably use a baseball bat in one hand and a feather duster in the other, and it still wouldn’t matter. It’s just something the brain needs to wrap itself around.
In case the insight helps, I find the greater the mass or length of the flogger, the more you substitute wrist for arm motion… basically just expand the radius of the rotation. And how you strike is also related to the radius.. the smaller the flogger, the easier to concentrate on a small area, larger, the easier to expand the strikes over a larger area. At least that’s been the case for me.