Spring gave us a good teaser and left again, hopefully we will see those warmer temperatures soon.
Yellow rocket can be a real challenge to get rid of, but doesn't pose a serious threat to the clover. Fescue and other grasses are what suppresses and chokes out clover the most, although it's exactly like Dogghr mentioned, there's never a clear winner in the grass/clover struggle for supremacy, they usually each end up controlling patches and areas in an unsprayed field, therefore, the deer always will have some clover patches to graze, and this is a good method or having low maintenance wildlife plots if one has sufficient acreage to make it work.
I'd suggest either spraying a clover field correctly, which takes very little chemical, but needs to be done on schedule, thus totally keeping the plot weed free, or not spraying at all and letting nature keep the balance. An in-between stance of spraying sometimes, but just letting the weeds go sometimes, usually ends up dumping a lot of chemicals on a field with no clear results.