Can I trust the people of my gym?

Hello there, Fititt!

I've done Rippetoe's 3x5 (rows instead of power cleans though) for about 2-3 months now and got addicted to weight-lifting. I changed from my previous gym (1000 cardio machines, 1 squat rack) to a hardcore powerlifting/strongman/bodybuilding one. The people here are awesome, the equipment is awesome and it's awesome all around. One of the people here holds a world record (I've seen the certificate), at least one is quite accomplished in power lifting (world champion league I heard, not sure) and there are several successful bodybuilders. Based on that, I would think that the coach/owner of the gym must be pretty knowledgeable too.

However, he (used to powerlift/was a strongman) recommends something completely different than the 3x5 system:

Day 1:

• Shoulder Press (Alternate Barbell and Dumbell each week), warm up with narrow grip benchpress (50% of regular bench press weight)
• Shoulder Fly
• Pull Ups (Both narrow & wide/regular grip)
• Biceps Curls
• Shrugs

Day 2:

• Squat
• Deadlift

Day 3:

• Benchpress
• Benchpress narrow grip
• Butterfly
• Triceps (Skull Crushers or something like that)
• Shrugs

My friend told him that our goal was to enter Strongman contests eventually and the gym owner told us this plan. Is it good? Should I do Rippetoe's 3x5 instead? If yes, how should I go about telling him? As I already mentioned, my goal is to enter Strongman contests and look awesome (bear mode!).

If it helps, here are my current stats after about 2-3 months of Rippetoe:

• Weight: 120-140kg / 265-308lbs
• Squat: 3x5 @ 140-150kg / 308-330lbs
• Deadlift: 3x5 @ 180-200kg / 397-440lbs
• Benchpress: 3x5 @ about 90kg/198lbs
• Overhead Press: sooo low :(

Ranges of weight because it changed a lot and because of a 5 month break I had to take when my mother passed away, just started going to the gym again. Weight will go down again, as I just started counting kcal again (lost 20kg like that, but stopped doing it instead of making it a permanent change).

So yeah, please tell me how to proceed. Should I do the regular 3x5, or what?