No, that's not the way you can do it in the slow cooker as you'll end up with a messy mash.
Firstly, oil the crock pot and add some sauce ( I use passata) then layer in the pasta plus garnish. Add less sauce ( I don't use béchamel) than usual. I add more sauce on the top and finally the slices of cheese. The pasta can be broke into unequal sizes as it all comes out ok in the end. With slow cooker lasagne, you really do have to check to see whether you have enough liquid form time to time. I just add a tiny bit of stock if necessary but you don't want it to wet if not you'll end up with a mess.
Did you see the photo of the lasagne and the distinct layers, that I posted above ?
Edit : It also comes out far better if you cook it the day before and leave to cool before reheating it. The slices are far neater.