It's nothing new. Back in the 90's some GMs would draft OTs with OG traits, i.e. shorter like 6'5". They normally had longer arms than most OGs and generally were more athletic and with better feet. They would redshirt them one year building them up physically, and coaching them up on the technique differences. Generally however, if they wanted to run a power scheme they would do so with a road grader type of FB as a lead blocker otherwise they were just fine if they ran a zone blocking scheme.
If McVay doesn't want to have a FB he should stick to zone blocking schemes, inside and outside. But we all saw the limitations of those run blocking schemes which is why they transitioned to a more gap blocking scheme. Now McVay wants to run an inside power scheme because it lends itself better to play action. But because his OL is built of OT type players they lack the road grading OGs to do it consistently. Ergo he needs to take a page from the old offensive playbooks and use a FB instead of a wham blocking WR or TE.
This is why for two years I've been saying McVay needs to decide what kind of run attack does he want to run. The problem with zone blocked schemes they are less effective in short yardage where the box is stacked. Which is why the Niners use a FB. They will run it down your throat until you stack the box. Then they will play action and pass it over that stacked box.