[/B]Additional Glute Work
The glutes are heavily involed in the Squat and Lunge.
Exactly, how much more glute does he need?
The more glute work the better, since it's a secondary muscle. The extra strength gained will improve his DL, Squat, and Lunges.
Grip
His grip is worked with his heavier SLDL. While the SLDL can build grip strength that is not the purpose of the movement. It is a posterior chain exercise, not a grip movement.
Improving one's grip with the SLDL is an ancillary beneift. There are other more effective method of improving grip strength.
SLDL are not an effective method for improving grip strength? Seriously? I'm thinking that comes from people who don't do them
Form
Performing light weight for repetitions isn't very effective at developing one's technique. Research shows that as the percentages of the load change, so does the muscle invovement.
That means, the muscle firing order is different with 60% of 1 Repetition Max compared to 85% of 1 Repetition Max.
Tired Muscles
An additional problem one technique deteriates as the muscle fatigue. Thus, one ends up developing improper technique.
Confidence
Building strength builds confidence, not banging out repetitions with a lighter weight.
Completely disagree with all of this. I don't know where you read this, but it certianly isn't consistent with my experience.
Contadiction In Advice
Your emphasis is on performing additional lighter sets with higer repetitions with the SLDL to increase grip strength. Then you recommend performing Good Mornings, if he has grip problems. That is a contradictory advice.
Using straps in performing the SLDL would for the most part accomplish the same thing.
It's not a contradiction, it's a substitute until his grip strength progresses. I wouldn't recommend straps, since they could be tempting to use all the time.