Anemone, I'd take the opposite approach. I've looked at the profiles -- John McDonell shows some sources, but they're not linked to any of the facts in the narrative. The three Alexanders have no sourced data, and the Ancestry links go to a dead end. So the facts, you don't actually know anything about any of these people. If you were to do any merging, you would be merging three unknowns into one unknown, and it's hard to see why that would be worth the trouble!
Obviously you care to know something about them or you wouldn't have been looking at the profile and been frustrated by the confusion. So I'd suggest you do some research. Google Advanced search can produce some amazing resources when you tweak it with combinations of words that must be together plus a few other words that might be a lead, etc. The search engine right there on the page can give good results, too. I'd start with the sources on John just to see if there's anything there -- if tehre is, put the facts on the narrative section and give them sources so you know where the information is from. Then research the Alexanders. Look by the different dates shown in the respective data fields -- they might be nonsense, but they might actually be a real fact that just hasn't been documented. You may find that there are actually two or three different Alexanders; at present, the dates could fit two different generations. But if you do the research and put the facts you find -- with sources -- in the narrative of whichever profile seems most likely, then you'll know whether you need to merge or not, and have a factual basis for doing so.
Remember, any errors you make with the data field and the narrative section can be fixed by going back into changes and seeing what used to be there. But merges can't be undone. So I do merges at the end of a research process, not at the beginning!
