Short length big head 13 month old

[Purplelooby]

DS3 has always had a massive head and was born a decent size, but while his head continued to be big, his growth has been more sluggish. At the 12 month check his length was below the 0.4th but his head circumference was on the 98th. His weight dropped significantly as a newborn but he has tracked the 9th ever since.

Now he's a bit older, I can see next to other babies that he is all tummy and head. Shortness is in my family so I'm not overly bothered about his height, it's more the head and height combination. The measurements are being sent to my HV but while I'm waiting (and to prevent me Googling until 2 am), has anyone got any advice, words of wisdom, experiences to share, etc.?

Should add, his gross motor skills are a bit behind and at 6 months he was referred to a paed about them. She concluded low muscle town because he still had a head lag, but felt that while it was outside of the normal range, it was mild enough that he was likely to catch up. The rest of development is fine.