I would think most problems occur on the back cast or the cast. Everyone see these bass guys on tv whip a back cast and change directions, load the rod and whip it forwards. That is all great a weight ( the lure) attached at the end of the line. With a slip float and a jig being two weights attached at different points on the line. In the second scenario the if the same cast style is used the two weights pass each other when the cast transitions from backcast to forward cast. As this change of direction occurs the line whips around in a loop. A miniature version of a fly cast. Unless the float and the jig are grouped together ,then that close by pass allows the jig and float a chance to hit and tangle. The second chance is when the jig snaps to the end of it's line, and is slingshotted by the float. Moving the rod back allowing the jig and float to hang down, then smoothly accelerate the cast. Things go a lot smoother.
Play around with some cast when you have a minnow, splitshot and a float. Three points to effct each other in the cast. A slow deliberate back cast, stop and allow everything to hang down, then a smooth cast everything lands nicely. Get wild with it and the minnow can be tangled above the float.