If Frederick recovers back to his All-Pro form, that'll be huge. We know that Tyron and Martin will play like All-Pros for as long as they're healthy (and I'm feeling better about Tyron's health now than I did at this time last year), and Collins has improved to where he's an All-Pro or very close to it. Ramczyk and Lane Johnson are probably the class of the NFL at RT, but he's not far off.
LG's the only weak spot, and we even have a potential upgrade stashed there in Connor McGovern.
If Frederick recovers, this line could go 2014-16 death mode again. 4 out of 5 starters are absolute studs, and C-Will or McGovern just need to be the Doug Free.