Because each type of df requires different means.
The method he used to create zoan wasn't applicable on paramecia and logia.
He found another way to create artificial paramecia by taking lineage factor of present Paramecia df user and then creating Green blood out of it.
But this method didn't work on logia fruits.
I think it could be because it's difficult to take lineage factor of logia fruit user as they are elemental and non tangible or it could be that logia fruit are special class.
The method he used to create zoan wasn't applicable on paramecia and logia.
He found another way to create artificial paramecia by taking lineage factor of present Paramecia df user and then creating Green blood out of it.
But this method didn't work on logia fruits.
I think it could be because it's difficult to take lineage factor of logia fruit user as they are elemental and non tangible or it could be that logia fruit are special class.