Who has had success (or failures) with moving Fullbacks to Offensive Linemen? Even though they are smaller and shorter, they are faster with semilly equal strength and blocking skills. I personally like moving them to Guard positions so they can get blocks in the second layer against LBs.....but that's just my opinion.

Asking for a friend

In older game versions, this was an easy strategy because the FBs would slowly bulk up to offensive lineman weight and become effective, so long as their skills and attributes were ok. However, my understanding is that under the current game version, there is an extra hidden variable that prevents 100% effectiveness of that strategy. Each player has a hidden "body frame" rating. Thus, you cannot know when you convert a FB to OL that he will ever bulk up enough to be effective. It could be that his "body type" goes the other way, meaning, he's already near the top of his frame size, and instead could slim down to be an RB. While the FB would still have the skills, he might cap out at 270 pounds and be a smurf on the offensive line. On the other hand there is a chance it works out perfectly and he bulks up to 300.