Particle Manipulation

I've seen a few posts on here where OCs are capable of manipulating some kind of particle or small substance (i.e. sand, smoke, dust, leaves, etc.) and are being told that abilities like that require much heavyconditions because the quantitative control of several particles is too difficult for a manipulator. Meanwhile we have Morel, Kalluto, and Zakuro who do just that (I know Zakuro controls his blood that wouldn't necessarily be considered "particles" but it's still close).

Where is this idea coming from? I was under the impression that if the manipulator controls particles as a single unit, that this is possible with ease. I could see this as the case if the manipulator were to program each individual particle to behave differently (effectively programming thousands of command).