I think you might have misread something in TftNA. Refer to page 226 and beyond for the discussion of Max Strength methods. ON page 227 it very specifically states to rest 3-5 minutes between sets of the same exercises. One can alternate upper and lower body exercises so that the down time is less. Endurance athletes typically hate the rest period between sets so combing them into this mini circuit or ‘couplet’ style shortens the workout with dramatically compromising the results.
Using the couplet method we give 80TSS to the max strength workouts we use for clients or that occur in our training plans. This workout is similar to the ones in the book but includes 4 exercises for mountaineers, done in a couplet style. Box step ups and Pull ups in one couplet. Step downs and Push up in another couplet.