I think all four combinations are nice, but I like Astrid Alexandra Stanley and Jacob Benjamin Stanley the most
Madelyn McKenzie reminds my of my cousin Maddy, so I think blonde, cute, sweet. Unfortunately I've had a few negative connotations with McKenzie, so I'm not really a fan of the name. But this is all just my opinion.
With Astrid Alexandra, I love how well it flows with two A names. I think Astrid is a very strong, solid name, and I picture a smart, tough girl. Alexandra is also a nice smart name but the A and the end makes it more feminine and girly, going nicely with Astrid. I really love this combo.
I really like Jacob Benjamin Stanley. I know a few different Jacobs with completely opposite ages and personalities, so my 'view' of this name as a person is a bit hazy.
Lyell Sullivan Stanley is nice, but I feel like it's a bit dated compared to your other name choices. I first picture an older man, but I can also see a cute little boy with this name.
I feel that no matter which name you pick you'll make a good decision. Good luck, though!