Given the fact that Catalans have a better team than Wakefield (when all registered players are available) and that Catalans are not guaranteed to make the Grand Final, I don't know why anyone would imagine that Wakefield would make the Grand Final.
The only strong probability for the Grand Final is St Helens, and even they were decisively defeated in the Challenge Cup semi-final last year by Catalans, as they were in Perpignan in the Super League round this year.. Catalans also defeated Warrington in the CC final in 2018, and in Super League at Perpignan this year. So if you are looking for an outsider to beat either St Helens or Warrington in the Super League semis, and thus make the Grand Final, it would be smarter to bet on Catalans.