If I'm being honest, there's unlikely to be anymore info. (online) than what you see in the Croft History book(s) as B Lawson actually travelled to Canada to source a lot of his info. which is more than what's on this side of the Atlantic.
If your gg g/father Angus named his 1st son James then that sort of throws things a bit with the names you have in mind (I think) i.e. Angus, Archibald or Alexander?
The MacDonald history for me is very difficult to follow as there were different Septs as well as illegitimacy.
I'm a MacDonald descendant myself but I don't seem to be from the Clanranald lot although my MacDonald connection was from S/Uist as far as I'm back (c1770)?
My 3 x g g/f Donald MacDonald c1791 married to Ann MacIntyre c1791 died after statutory records in 1856, one of his daughter's was the informant who named Donald's father as John, mother as Catherine but no surname so I've been sitting on that dyke for a lot of yrs.
The naming pattern of their children don't help me at all either...
1st child named Mary yet her mother was Flora, no child named John or Neil after wife Ann's father.
According to B Lawson the marriage was 1821 (not recorded) but a handy help!
Baptisms were Mary 1824, CATHERINE 1825-1889, Angus c1827, CATHERINE (2) 1828-1892, Flora 1831, Janet 1834 yet both Catherines lived long lives & named after Donald's mother so it's an enigma.
There's possibly room for a John or even twins prior to my 1st record for Mary found after marriage who would have been old enough to have left home (wishful thinking)
?
I have steered away from MacDonald research for many many yrs as they're in abundance (most popular name on S/Uist) but maybe on my travels I will fall upon a sibling or 2 of my Donald although I'm in no hurry as I could easily spend a fortune if I was desperate enough but it's a hobby not a chore & I always enjoy the unexpected finds which is usually when helping others
Annie