I have a major league issue here

So we are in a 10 team 0.5 PPR league the problem here is that one guy in our league has a STACKED team meaning thay his roster looks like this.

Zeke, DJ, Adam’s, Kittle, MT, Bell and Adam’s… And I am looking over all of his trades and they all look fair outside of maybe Kittle for Hardman in week 2…

The thing is that I am a Firm believer in letting teams play but I am the commisher and they all looked fine at the time and it wasn’t one manager who did shitty trades it was the whole league who he got over on… I am trying to figure out how to I avoid this issue for next year cause I do not have the time to babysit trades to prevent this at all, I guess a league vote works but man that just seems so boring… This wasn’t a beginner league either at least it I didn’t think it was cause everyone has been playing for years and this is a 4 year old league and we have never voted trades ever… So I cannot understand how this happened…

I am not even sure what my question is I think I am just venting here.