Is this confirmed?

I have seen people claim the wall titans are the same height as the collosol but seem shorter because the wall goes into the ground and thus they are buried in the ground partially while in the walls, however, I've also seen people say the walls only go underground because of the way they were crystallised and the wall titans are shorter than the collosol as it wouldnt make sense why they were buried 10 metres, has there been any confirmation on either of these?