A popular option, and the one I mostly use, is first image focus priority, then second and subsequent images in speed priority. In continuous drive mode, this ensures you start off with a sharply focused picture, and after that the system should stay sharp (provided you can keep the AF point accurately nailed) and rattle along at full speed.
Many cameras offer much more customisation options than that for continuous servo tracking, and it's important to know what's what, in line with the kind of subject you're shooting for the highest hit rate. It makes a difference. Servo tracking is difficult for both the camera and photographer - the camera needs a good lens, preferably with a low maximum f/number like f/2.8, and a nice contrasty area (both light and darker tones) of the subject to lock on to. For the photographer, it's a skill requiring both knowledge and practise.