Star Trek Realities

[Granitehewer]

Hi everyone
I'm penning a series of alternate universe stories which I'm trying to link in with as many existing episodes of the franchise as possible, and was hoping to stick related queries here rather than clog up the other threads with my ramblings.
Firstly one of the tales is set in the 'Yesterdays' Enterprise' universe and features a crippled federation 'assisted' by a reluctant Romulan Star Empire, in part, due to elements within the empire being concerned that shutting their borders may not hold back a tide of bloodthirsty klingons once the UFP is taken, and also due to a successful operation by section 31.
I was wondering, 'The Die is Cast' mentions that cloaked romulan vessels are more likely to be detected at warp 5 or above (althought this may not apply to the ''perfect cloak'' in st:nemesis), does anyone know whether this applies to klingon or Breen ships?
regards to you all
pete