In my league as the Commish, my policy is to approve all trades as well. If/when one comes across that I think is just flat out cheating, I put it to a league vote. Before this rule was put into place we had tons of problems with trades, since then, no issues at all. I think the league knowing before hand that cheating wont cut it, goes a long way to deter it. In the end, your job is to keep people honest, not intelleigent. I cant tell you how many times a trade as come to me and I say it sucks, untill three trades later when I've wished I had thought of that.