Before I say anything. This is not a Total Body Training vs. splits question.
Many of the TBT/High Frequency guys will say that you should not rely on stimuli like fatigue and ‘pump’ to gauge your workout.
However, are the rules different for splits/lower frequency training? Is the ‘feeling’ much more important for this approach? Should we rely a lot on feeling in order to gauge things? For example, if you feel like your biceps could use more work, throw in a few more sets? (Assuming biceps were among the muscles that were specifically trained that day)