*Figured out, how to "solve" this problem
The problem is somehow connected with how the 3dsimed understands smooth groups. As I understood, it shows a correct number of points if there is only one smooth group (or no groups). If we try to import a model that contains 2 or more smooth groups, 3dsimed duplicates every vertex for each poly. To avoid this:
1. Export from 3dsimed in .3ds or .dae.
2. In 3d max (or any other editor) to make a smooth group, select polys and detach them to new object
3. Export from 3d editor in .3ds format.
4. Import .3ds to 3dsimed, now a model consists of some number of objects and they all look separated like smooth groups. And 3dsimed shows exactly the same number of points as the 3d editor.
5. Explode all objects.
6. Export in NFS Shift format. Borders between groups of polys remain just as they should be.