Somehow, a capsule (for 3), a service module, and an orbital module are a better solution !

The orbital module is the little difference: it stays in orbit, therefore it can be used :
To build a space station (adding modules one mission after the other).

As a logistics module for that space station.

As an unmanned but man-tended platform.

To spend more time autonomously in orbit.

All this with the same rocket as the one used for the Shenzhou spaceship.

There is no real need for more than 2 spacemen aboard a space station if the purpose is to occupy space and study very long weightlessness exposure. There is therefore no need for many modules (brought with the Shenzhou):
A core module with 6 docking hatches.
A habitat module (for 2 or 3).
A spacewalk module (with airlocks and spacesuits)
A science module
A power module (solar energy and/or Fuel Cell module)
A logistics module (with fuel and/or food).
A docked Shenzhou

(A core module and 6 others docked to every one of its sides, a beautiful cristal-like station in orbit).
Of course, the solar panels could modify its shape. But , just like with Mir, those solar panels could change place, be added to or removed from modules and this would require spacewalks!
And tourists or other nations would be welcome!

Raoul