Huh I thought the one story they did was the origin story, since it has the appearance of the first Cybermen (well they had a few around already) and Mondas had some people still. I forget the name but I think it’s #5 and Nyssa, this sounds like it may be a bit before that but also sounds like the doctor may trip over himself if it’s not much earlier.
I’ll admit, I found first three doctors more rough to watch and only watched a handful of 1-3, more 3 than 1 and 2 for sure. Does make me curious on those episodes though, I do enjoy seeing first and early appearances of major characters/species in series when they’re still being fleshed out.