My bosses in that job were smart, and HR was a waste of air. The basic criteria we had on dress - wear what you would wear to look good on the job - but not for my bosses job!
I was in machine shop and assembly - and you're both right, kind of. For me, I'd like to see an applicant in appropriate footwear - meaning safety toes if the job requires them, and sneakers, hikers or work boots that are up to pounding concrete all day and don't make you look like an f'n bum. Jeans, cords or kakhis are good, NO HOLES (can get you a safety gig in these jobs) and pulled up over your ass! I'd go with the polo, an appropriate collared shirt, or MAYBE a NICE T-shirt - any graphic or slogan on said shirt should reflect well on the wearer and the job. No tanks or baby tees.
We only ever had 2 guys in suits apply. One showed up in his "Marry and Bury" suit - his own, well fitted (he was a big galoot, like me), looked comfortable - we hired a good electrican.
The other guy (can't make this shit up!) was wearing a brown leisure suit with Elvis hair and a half-gallon of cheeep cologne. Did'nt get the job.....