Yeah that's a bit crappy... I have noticed in the past though that Misty and Nelio aren't always the best of communicators with each other

I requested that an invoice be sent for final payment, and had to chase it up for over a month, it just never came through. Turns out Misty thought Nelio had sent it, and Nelio thought Misty had sent it...

Any way, my point is, is that Misty might be fine with doing your timeline, but Nelio doesn't know that, so he's letting you know what they usually do... I don't know, I'm just hoping this is the case...
You just tell them the time you want them to turn up. I'm sure they will work with you. Especially if you tell them you want them there for the DP, and not so much the getting ready pics. Surely they'll get it...
Let us know how it turns out