Go with your plan but be ready to change it up and go with the flow if needed.
Also make sure you’re at the front of the pack at Adventureland and take that route toward Frontierland.
We went to rope drop Thunder & Splash on Wednesday, a normal 9am opening. When we reached the area, there was a mob of people coming from the other direction and we were very lucky to be let through and into the line at Thunder just before that giant group because Splash was down, causing a lot of confusion and really massive crowds really early on at Thunder. There’s really no other ride nearby to take any of those people rushing to get on something ASAP. Splash, as well as Haunted Mansion, ended up both being down pretty much all morning.
Even with two rides not operating, they still ran only one track on Thunder. When we got out, that standby line easily looked like an hour wait...