THE MANNIFESTO: VOLUME I, CHAPTER IV
Throughout the Mannifesto, Stannis is repeatedly granted almost superhuman powers of secrecy and deduction. The first three essays (The Night Lamp, Subverting Betrayal and Operating in the Dark) alone suggest that Stannis was pursuing goals and using strategies that he did not reveal to even his closest confidants unless necessary.
Stannis is executing his northern campaign with an extreme level of secrecy.
The truth is that Stannis’s conspiratorial nature—particularly in A Dance with Dragons—is necessary, due to factors that we can readily prove:
Stannis was aware of ‘untrustables’ in his midst at Castle Black, most especially concerning letter handling. Subsequently Stannis did not entirely trust the security/privacy of messages at Castle Black, nor did he trust his secrets to anyone that did not need to know.
Thus, the idea that Stannis is operating a “conspiracy” is not the product of reader bias, but of strategic necessity.