It took Rand a few moments to decide to balefire the entire site. How long did Graendal really have with Ramshalan? Even if it was under thirty minutes or an hour, I don't think we have enough info to project the amount of time or the severity of the Compulsion. Keep in mind, that some people, including Aviendha and Mat, still dimly recall their deaths and some people were surprised they survived.

Balefire is more complicated than a simple prediction based on theory - mainly because the Pattern is interconnected along various points of it's warp and weft, and it doesn't necessarily travel in a single line of cause-and-effect (ie: some people aren't affected by Person A's erasure, but if Person A's erasure causes other people, say Person Z to feel some effect, they may feel the temporal backlash or the instability - personally, this is why I think so many weird things are happening).