I guess that it depends on what you are trying to achieve. The original post seemed to want a multi purpose workout covering speed, fat loss, endurance etc. but retaining a twice a week format.
I think that either approach could work depending on what else you are doing during the week and what your needs are. If there is a specific need in your sport or your particular case for enhanced anaerobic endurance and you are training x 2 a week then you may well have to look at hybrid sessions including speed first followed by speed endurance so that you are working each attribute twice a week.
I am not sure what you have in mind regarding the four sprint sessions but do remember that under the CFTS there are only 2-3 high intensity sessions a week and that weights FOLLOW the track sessions.
One final point. I did not mention drills in my original post. They are normally a feature of a track sprinters workout but I did not think them relevant in the context of the original question.