Hello, I agree that it's generally easiest to start with the most distant ancestor and work your way forward.
You might want to keep these pointers in mind:
1. You can usually send a message to the manager of the other profile. Some people will be delighted to hear from you.
2. Of course the manager of the other tree might not be active on wikitree anymore. In that case, simply wait a month, and the the merge will be automatically opened for you to complete.
3. To facilitate merges, make sure that the profile you want to merge is well-documented. Right now Francis McCall has only one source -- a big web page with a whole lot of information on it. This isn't very helpful. For example, Francis's profile shows the names of his parents. What is the source for that? A Bible record? A land record? Grandpa's memory of what his grandpa told him? Is it just somebody's guess at ancestry.com? Does that website mention the source for Francis's parents? If so, it's a good idea to put that information into the wikitree profile. The same with Francis's birth and death dates. Is there a gravestone? If so, where?
If your profile is well-sourced, it looks a lot more trustworthy, and people will be less likely to object to the merge. I wouldn't worry about editing a profile while waiting for a merge, especially when (as in this case) the other profile doesn't have any information at all.
4. If you are sure of your facts, and if you have waited a couple weeks with no reply from the other profile manager, there's no reason not to edit the other profile while you're waiting for a merge. For example, you could link the parents (if you have proof), because the other profile doesn't show the parents. Of course you have to be careful and diplomatic if the other manager suddenly appears, but the whole point of wikitree is to collaborate on a single profile for each person.