I'm guessing you are talking about UDFA's Tony Romo and Miles Austin and 7th rounder Jay Ratliff. None of whom started opening day their rookie years.
Ratliff played in 4, started 1 his rookie season. Started no games his second year and became a fulltime starter in his 3rd season.
Romo played in 0 games his rookie year and just 6 games his next year. He wasn't a starter until just under the halfway point of his 4th year.
Same deal with Austin, wasn't a starter until halfway through his 4th year.
Nothing wrong with developing undrafted or low round picks. They shouldn't be your starters going into their rookie season unless your team was devastated by injuries. This is a result of God awful planning and a belief in a certain GM's wanting to show he can find players no one else can and show that he is smarter than everyone. If Nagy came into camp and blew the doors off everyone and beat out an experienced veteran, I would back off. He didn't. Holland was pretty much out all of camp. He beat out a small school rookie and UDFA rookies.
So what you're saying is that there is zero percent chance that we improved our team with our offensive line decisions?