The Soyuz is made up of three major components/modules.
The Orbital module on top, basically a sphere, which is basically extra room, and contains the toilet, which allows for some modicum of privacy. It is discarded when reentering. (The Shenzou approach leaves its analog to this module orbiting with experiments, which is quite clever)
The Descent module, in the middle, sort of gumdrop shaped, is where the astronauts reside for launch and reentry. This is reported to be very cramped and tight on space.
The Propulsion module at the bottom contains the engines, solar panels, etc.
However, during a launch abort, the first two modules need to be pulled away from the launch vehicle. Why is the manned component in the middle? Did it not make more sense to have the people at the very top, thus allowing a simpler abort (less mass to pull away)?
I am pretty sure Soyuz uses a tractor (not pusher) abort system.