There weakness was there lack of experience.Will see if they can learn. Noteboom last & Allen can both bulk up. That is the advantage along with extra training camp in house with Reggie Scott.
There is a problem So Ram with both these OL'ers. On Kromers selected starting center in 2019...Brian Allen .....he is max'd out already physically.
He is under 6-1 listed around 305. BA is physically mature as he is going to get. He might even be too puffed up IMO. I would expect that Kromer will make him starter on Team OL #1 @ center early this 2020. I would bet that we see BA start & play for the first half of 3 of the 4 preseason games too. BA biggest need is experience & he could have used an extra full season getting blended into being the lead for the starter position @ OC in 2020. But I also expect that Kromer is going to have a veteran with some starting experience @ OC in his OL cadre.
Kromers current main back up to BA will be Coleman Shelton. Now Shelton is a different body type 6-5 300lbs he will need as you mentioned above some serious bulk up work assignments from this point through TC & preseason. I believe he has a very good chance to make this 53 MR due to the fact he can play OG/RG/RT posts. His skillfulness & versatility will be his key to success. I would look for Shelton to be the #8th or #9 OL'er in 2020.
Onto Noteboom.....Noteboom has legs/calves much like Andrew Whitworth. You could have put both Noteboom calves inside just one Rodger Saffold Calf! Noteboom is not built anything like a Rodger Saffold, Quenton Nelson, Marshal Yanda or Zack Martin. JN's body type is far closer to Ronnie Stanley or David Bakhtiari who are the two best LT's in 2019.
JN was NOT a well-defined OL'er in 2019 & IMO
never should have been selected to start @ OG this season. Its obvious IF Kromer has gone a different route with JN where Joe would have been blended in tightly with Andrew Whitworth & Rob Havenstein used as an effective trio of OT's. When Big Rob was having game issues with small dinky quick pass rushers you would turn the RT post over to JN. The extra yr of OT experience would have put JN & the Rams LT post in a great position for 2020.
When you have a surgically reconstructed knee you will not have the opportunity to build much overall lower body core strength until summer. However, JN will be able to work the upper body muscle groups independently. When I see JN around the bye I expect to see a 6-5 315 to 320 pound LT who still needs lower body work but will be in very good upper body condition.