How to mitigate Triple Triad Tournament Cheating

Now I'm aware this does not happen on every server, and I don't know how prevalent this is. But on my server, for the last month, the same person has finished top in the rankings each week, only 3 matches have not been wins for them. First 3 weeks they had 19 wins each time, this week during roulette 20 wins. Other people are now starting to do it, current second place has 19 wins, again during roulette week.

One way I've heard people 'cheating' (I'm aware it's not against TOS), is they use at least 8 alts, setting up these alts against each other, one using a stronger deck, another a weaker deck, the weaker deck alt wins against the stronger deck alt until there is about 10 or so matches left, then their main beats this alt using a weaker deck. There may be other ways.

I don't want to focus on the individual cheaters, but do people have any suggestions on how this cheating could be mitigated. As essentially it just removes any enjoyment from this part of the game

I wasn't aware that this was a thing, and now that I am, and that this could unfairly lead to perfect win streaks for some players, that makes my quest to get the Cecil Harvey card even more frustrating now...

It would also majorly surprise me if this somehow didn't go against terms of service; it should.