When my DS was army crawling he could not pull up. It wasn't until he figured out how to put himself in the sitting position (from laying down) that he could pull up. He would sit then grab the couch and use his arms to pull up. All of that happened around the same time he figured out how to crawl with his belly off the ground.
Once he started pulling up, it was a week later he started cruising.
My DD couldn't pull up when she was army crawling. As soon as she learned to crawl on all fours and get into the sitting position herself, she started pulling up very shortly after that.
Re: Army crawling and pulling up?
When my DS was army crawling he could not pull up. It wasn't until he figured out how to put himself in the sitting position (from laying down) that he could pull up. He would sit then grab the couch and use his arms to pull up. All of that happened around the same time he figured out how to crawl with his belly off the ground.
Once he started pulling up, it was a week later he started cruising.