Of those five, my biggest concern would be Fluker's inability to pass protection as a guard due to slow feet, struggles at run blocking as a guard due to lack of explosiveness. He was decent as a RT with strong hands to turn smaller ends and good use of his length on the outside. His grades at tackle have always been better than at guard.
Pocic has the excuse that he was an undersized rookie with average athleticism. Now, he has at least gained some weight. They'll give him every opportunity to sink or swim at the LG position in his second year.
Ifedi is still playing out of position at RT, but options are limited there. Fant is coming off an injury and lacks technique. Because he played RT in college, which means next to nothing, Ifedi believes he should stay at RT. James Carpenter had the good sense to ask for a move to guard.
Even with these concerns, on the whole, this is the most talented group we have had at the offensive line since 2014. In 2015, they traded away their center, Max Unger, and signed or drafted no one to replace him. They also let James Carpenter leave in free agency without finding an adequate replacement. In 2016, they did the same thing with their LT, Russell Okung, and their RG, J.R. Sweezy. In 2017, they were going to ride without a legitimate LT, until they had the good sense to trade for Duane Brown, mid-season.
From 2015 until Duane Brown was acquired in 2017, the offensive line was a shit show from a personnel perspective; front office has seemingly never taken responsibility for that. They blamed the overall lack of talent in college for fielding the worst offensive line in the NFL during that time period. The scouting department has been promoting from within, rather than adding an offensive line expert who would carry more weight in assembling a functioning unit.
Ifedi and Pocic absolutely should improve, in all phases, due to the technical coaching they will receive from Solari. I'm intrigued by the strength and athleticism of Jordan Roos and Skyler Phillips, as backup guards. I'm interested to see whether they will get any play with the first team or whether Solari will be more focused on improving the technique of these five.