That is a good question... I had never seen a drawing like the one I found in wikipedia - not sure if that is this is the one you are referring to or not? Ours are listed in our five element theory section - and you are correct they are slightly different within certain texts, etc.
<img height="500" align="middle" width="440" src="/files/u2/FiveElementsCycleBalanceImbalance.jpg" alt=""/>
I believe the issue here is just a matter of semantics, rather than two different theories. It's also a matter of elemental reality, for lack of a better way of saying it. My understanding is this.... If Fire, for example, is excessive it is going to overact (cheng cycle) on Metal - but this overactivity means that it will overwhelm the Earth element as well - just by the nature of the realtionships. So in this drawing this latter activity is called "overacting" (you could say over generating) and then they use the ke cycle which in many drawings simply shows the "controlling/balancing" relationship as a destruction cycle. In reality both drawings show the same relationships they only differ in their description of the negative side of the relationships.
<img height="252" align="middle" width="252" src="/files/u2/ke_cycle.gif" alt=""/>
<img height="252" width="252" src="/files/u2/cheng_cycle.gif" alt=""/>
Does that help?