A few points to consider:
1) Gross gave up six sacks, Bell gave up nine--but take away the Bills game, and Bell gave up less than Gross the rest of the year--yes there were the pressures, but in the Painfully slow Shula offensive, every tackle will give up pressures.
2) There was no tight end help In a one tight end scheme where he is the leading receiver. Bell was on as much if an island as Gross--not much running back help either.
3) how many guards lined up next to Bell? O-line needs to gel more than any other position group, and These guys never had a chance.
G-man drafted healthy, young guard, and great blocking running back--new offensive consultant brought in as well, so all the above problems have been addressed.
4) Nate Chandler has played well, is young and very coachable, and is 6-5, 310, 4.92 speed. If an SEC tackled has those numbers, the experts will give them a first round grade--what second tier tackle could be better?
5) G-man did better than draft a late round tackle--he pulled a drafted rookie hog mollie from the Steelers practice squad--now has a year of NFL coaching and weight training, and didn't cost a draft pick.
Maybe the answer is already on the roster--I think that if this O-line stays healthy, they have a chance to be very good.