If you move the cg back you can reach that stall angle at a higher airspeed,
Aft CG REDUCES stall speed, not increases stall speed as you indicated. Stall angle is reached at different speeds due to, but not limited to, wing loading and CG.
Please see
http://www.copanational.org/non-memb...etyPPOct99.htm
Here is an excerpt from this page -
An aft CG location, while lowering an aircraft’s stall speed, is the most dangerous because with extreme aft CG positions it may be impossible to pitch down to reduce the angle of attack to recover from the stall.
AND
High power settings can also slightly reduce stall speed. This is because at high power settings, the thrust produced by the propeller is slightly downward, so the wings don’t have to generate quite as much lift.
Bob