So I have this problem that my plants tend to have an unreasonably high vertex count while the face count is OK. I sort of know how this occurs now, but do not really understand why.

This is what happens: let's say I have an existing plant with flowers and want to make the flowers fuller. I import the mesh into UVMapper Pro and assign the various parts to new materials. I then import the mesh into Wings3D and duplicate it. I remove the leaves from the duplicate by selecting all faces that are labelled 'leaves', and clicking Faces->.Hole. This leaves a second set of flowers, which I then move around.
I then combine the two, export, turn it into a single group with UV Mapper classic, and import into SimPE.

Simple, isn't it?

Only upon importing, SimPE seems to remember all the original vertex counts of the subsets that were used to make the final mesh. Here is an example: this mesh has 1371 vertices in Wings (and the UV-Mappers) and 2287 in SimPE.

Here, the first SimPE screenshot shows what SimPE thinks is in my mesh shown above in the Wings screenshot. The second just shows that making the mesh into a single group has no effect on the vertex count. (Neither does removing groups/materials in Wings.)

I'm totally perplexed at these ghost vertices, and would be grateful for any tip on how to avoid them. I am attaching a zip with the example OBJ, if anyone would want to have a look. Thank you in advance.