Well I have no idea if that's true; the PT III comes with a dual coil, and replacement coils for it are dual coil. About the minis, I don't know, except the PT II mini is single coil; I have one of those myself. For the Aerotank, I have no idea, though I suspect it's a dual coil also, since it's kinda Kanger's answer to the Nautilus, and that would mean its replacement coils are dual too.
If you're rebuilding coils, and know how to use a single instead of a dual in a dual-coil tank, then sure, I guess anything is possible. But what you can buy for dual coil tanks are stock dual coils; I don't think you can mix 'n match the stock coils. Especially not between the single-coil tanks and the dual-coil tanks.
If something says "uses Protank/Evod/Universal coils" then it's single coil, and you can use those kinds of coils in them -- like the Hypertank and Hypertank II for example. If it says "uses PT III coils" then it's dual coil. I suppose it's possible to try and mix 'n match, but I have no idea what the result would be. T3S's are single coil, but as far as I know, you can't use the Protank/Evod/Universal in them, they have their own coils, and those are also usable in the MT3S.
Hope that's helpful, in any way; the only dual-coil tank I've ever bought was the Nautilus, and I absolutely hated it; the airflow made it so cool at first I couldn't tell I was getting anything, then it would suddenly get so hot I'd have to yank it away quick or burn my lips; it also changed the taste of my favorite ejuice drastically, so that I didn't even like it anymore. Dual-coil cartos also suck, they just taste burned, and make the juice taste burned. Other than that, I have no experience with dual coils -- and don't want anymore!
Andria