If Chris Lawrence is not a good mentor, then I struggle to name someone else who meets his standing.
Lawrence is a top bloke and was a tremendous centre, but he's never been much more than a replacement level second rower.
Hoffman was close to, if not the best second rower in the world at his peak. He'd know exactly what special efforts are required to get there - extra cardio and/or strength work, eating better, mental preparation, whatever.
The coaching staff will definitely help, but you need to do a bit extra if you want to be the very best. Especially if our facilities are as inferior to others as reported.
Remember the story about Blair doing extra work when he was here?
http://www.weststigersforum.com/viewtopic.php?t=25437
I mentioned Lawrence specifically for his knowledge/qualification in the areas you highlighted, not withstanding their respective playing abilities as second rowers, but he also represented his country before his hip/hamstring complications.
Also it's a mistake to assume that better players make better coaches / mentors, if that was the implication Lawrence vs Hoffman. Trent Robinson wasn't much of a footballer, good coach though.