Yeah, the partwork is doing them out of order. It'll eventually cover every episode. Issue 2 is Colony In Space, The Daemons, and Day of the Daleks (Third Doctor, season 8/9), issue 3 is Deep Breath and Into The Dalek (Twelfth Doctor, series 8/season 34), and issue 4 is An Unearthly Child and The Daleks (First Doctor, season 1), which for some reason are referred to on the cover as 100,000BC and The Mutants (The Mutants is the name of another serial from season 9, for crying out loud - why on Earth aren't they using the same names as the DVDs?)
As P.Cobbold Esq. has mentioned, up until the last two serials of Series 3, each episode had an individual title, rather than "Monster Of The Week - Episode 1" format we were used to for the rest.
The first serial has been given several names - 100,000BC, An Unearthly Child, The Tribe of Gum, The Stone Age etc... 100,000BC was used at the time, so many people think that's the most accurate title.
As for the second serial, that is nowadays known as "The Daleks" but only since 1980. When, as you say, a serial emerged with "The Mutants" as its title, from 1972 onwards the original serial was known as "The Dead Planet." But from 1963 to 1972, it was called "The Mutants".