First off, again, if it is a patchwerk fight (which we occasionally have) then there ARE NO STRATS
Secondly, even if there are strats, they could be a trivial problem at best thanks to shit like ice flows or shimmer.
Third, even if the fight isn't patchwerk, it will inevitably become patchwerk thanks to gear. Think blackfuse. Think Brackenspore.
If the fight is heavy movement and heavy swapping and just generally fucking with your spec, then simc won't help, no. But neither will LFR due to unrealistic timers. LFR won't kill adds as fast as your guild etc
now if you're talking about progression, thats even easier. You will be wiping on bosses that are reasonably difficulty 50-100 times. You'll know the times like the back of your hand. 37-45 seconds roughly between this phase and that phase, ok what spell does that line up with (and so on)
SimC is merely the template or the starting point. After that your dps is about your fight length and your knowledge of it.
LFR is just poisoning the well against that.
You are getting stuck on the LFR point, I didn't even mention LFR because I don't consider it real raiding.
The point I'm trying to make is that although I appreciate simcraft and their values I only trust them to a point because we rarely have fights like that. I trust the actual log statistics from WoL much more when it comes to whats actually performing and what isn't. Simcraft is purely theoretical, its no different then if we look at science.
Simple example is this, pretend we know nothing about the boiling point of water
Theoretically lets say we calculate it to be roughly between 100 degrees and 102 degrees, depending on composition of the water
Practically when actually attempting to boil the water it turns out the actual number is between 104-106, depending on the composition of the water.
The number that we will care about more in reality is the practical results because the theoretical results aren't the reality.