1. lit. military tactics on paper (idiom)

2. fig. theoretical discussion that is worse than useless in practice

3. armchair strategist

4. idle theorizing

5. cf Zhao Kuo 赵括 (ZhàoKuò) leading an army of 400,000 to total annihilation at battle of Changping 长平之战 (ChángpíngzhīZhàn) in 260 BC