Degraded performance at the end of fullbody workout: Junk volume or still valuable?

Hey fitness folks! Need some advice on my full-body routine. Today, I left lateral raises for last because the machine was occupied. By the time I got there, I was exhausted (hit PRs on bench press and preacher curls!). Ended up failing at around 14 reps for lateral raises, while last session I managed 22.

Some context:

  • I typically do full-body workouts 3x a week
  • Cable lateral raises are my main shoulder isolation exercise
  • I've been progressing by increasing reps, aiming to bump up the weight once I hit 25 reps
  • I usually follow the same order (chest -> back -> shoulders -> legs -> biceps/triceps)

Questions:

  1. Was this a junk set? Should I have skipped it and tried again next session?
  2. Is this common in full-body routines? I enjoy the program but I'm open to tweaks.
  3. Should I consider drop sets or rest-pause techniques for exercises at the end of my workout?
  4. Is it worth pre-exhausting larger muscle groups to save energy for smaller ones at the end?
  5. Do you typically see reduced performance in later exercises during full-body workouts?

I'm curious about your experiences and any suggestions you might have. Thanks in advance!