The Vlad 3B experiment was fine. His strong accurate arm was a good reason to see if he could handle it. The work he put in on his footwork etc will serve him well at 1B. He can also now play 3B for a short time if necessary due to injury, etc.
It made sense to start him at the highest value defensive position he might be able to handle, and move him down the spectrum if not. Like pitchers, develop them as starters until they show they aren't cut out for it.