I throw as much stuff as I can think of into my clover in the early spring and again around the hottest part of the summer. And I don't count any of the wildflowers as weeds, even though one or two of them are invasive. They behave for me, so I don't get too worked up about it. Sedge is about the only one that holds back my clover. The rest seem to exist with it just fine.Adding other ingredients to a clover plot is a wonderful thing, that is, until weeds get going, which is inevitable. Once weeds happen the herbicide options are very limited in mixtures, if it's only clover and chicory Imazamox will work, but only cleans up well if used early in the season when weeds are small.
The best rule of thumb is, if a plot is designated to be very longterm, like four years or longer, it's best to work with only ladino clover. If a plot is planned for 2-3 years chicory and clover work well. If a plot is for one season or one year a multiple mix planting like annual clover, brassica, wheat, oats etc. works well.
I work really hard to assault my clover with anything else I can get to grow in it; things I choose anyway. This year, I've already thrown in pak choi, willowherb, flax, brassicas, forage oats, spring wheat, and barley. When I come through and mow midsummer, that takes care of about everything and then I throw the cereals at it again to prep for cool season.