I've not heard of tarts kickers
Prior to Emil's injury a couple of season's back he was flying in the GP's and I for one expect he would have made World Champion that year. Had he been in the GP's this year I believe he and Tai would have been the top 2. In any sport a competitor can only compete against the people put in front of him, and that goes for Emil as well as Tai. We will never know if Emil would have won this year, neither does Tai but neither were given the chance to find out. The series is diminished without the best riders taking part so by extension the winner's achievements are diminished (slightly). It follows therefore that Emil's 2 European titles are (slightly) diminished by Tai's absence from the series.
To be considered the best one has to beat the best and as, in my opinion, Tai and Emil are the joint best both should be in both series. In that way both World and European Championships (and champions) are enhanced.