固守四平 where the enemy was strong violated Mao's military thoughts as espoused in 中国革命战争的战略问题, 战争和战略问题, etc. Only Mao Knows why he wanted to 固守四平, may be for political consideration.
蒋 was a true Red agent? hee hee. Joke aside, it shows 蒋 was too narrow-minded, and narrow hearted to be a good military leader, let alone great leader.
We gave too much credit to Mao. Perhaps, Mao's counterpart was too weak to be effective.