I think it is not as unusual. All my asso mates dont spend I guess and often win trebles. In last 8 seasons, since I farm greens and read forum, won 5 trebles and 3 doubles. Through that time also saved 3k greens and 1,7k tokens. My 2nd team with almost no farming and rare attending almost won a treble once, lost a close final.
I dont think it needs any special skills or big luck, just following few basic rules. The system trying to punish non-buyers is for me a myth.