I cannot answer the Walmart question, as I have never done it, but I can tell you I have always rope dropped, mostly because I am a morning person, and I enjoy using the bus. Maybe if I share my experience, it will help give you something to consider to help you decide.
Usually I get a bus about an hour before park opening and it is so calm and peaceful. I will grab a danish or some coffee from the hotel and eat it on the way, take photos of the sunrise, etc. I will get a times guide and look to confirm nothing has changed and my TP times line up with actual show times, etc. The buses come well before the park opens so you only have to worry about how crowded it is, and the bus filling up if you wait until about 30 min before park opening to leave your resort. Also, the bus drops you off right near the front, where I have heard some ride-shares drop you have at the TTC. I have heard only Lyft Minnie Vans will drop you off where the buses do.
So I guess it depends on how you feel about a bus and what works best for you and your family. Hope this helps give you something to consider.