Ummmm, there is nothing about that sumo baby of yours that screams FTT! Don't mean to laugh at your concern but seriously D is FINE. Even my DD who is teeny tiny is still on the official growth chart. As long as D is meeting milestones, which he is, I think he's fine.
I'm getting DD evaluated tomorrow morning because I don't think she's meeting developmental milestones. That's not uncommon w/heart babies for a variety of reasons so if she needs intervention, I would like to get that started ASAP. A lady is going to come to our house at 8:30 AM (good lord! I told her not to expect too much out of my appearance!) to evaluate DD and then talk to the therapists to see if a care plan needs to be developed.