Oh dippymare, what absolute tosh. My DDs have been at CMs since 8 months, both settled immediately and happily, having naps in rooms much less dark and more noisy than at home. If they are good sleepers, they are good sleepers, if not then no routine, GF or not, will change that.
My CM always says what lovely adaptable kids I've got, and thanks heaven that they have a good sleep in the day so aren't screaming nightmares like some of her other mindees.
GF is not inflexible, and it worked fine for me. Won't for others. Same as FF/BF, CC/anti-CC, BLW/purees, blah blah blah, yawn yawn. Everyone does things their own way, its life. There is no right answer.
Hmmm, is this is a pro/anti SWSNBN thread by stealth?
What's your point OP? You'll be getting 'advice' from everyone, on everything - its called being a mum - just ignore it if its not relevant to you.