BH, it's lovely that you have such faith in paediatricians, but you are speaking from a US-centric position, and it's just not appropriate for you to talk to UK mothers as if you had the monopoly on correct information.
In the UK, paediatricians deal with sick kids, in the main. They have very little experience with well babies, and mothers can't just 'ask any paediatrician' about their babies' iron needs. If they did, because they were seeing the paed for some other reason, I am pretty sure the paed would have to look up current recommendations , which do not contain routine iron supps, because we don't have the problem of iron deficiency among young babies here. The US define iron deficiency differently (lower threshold) and have different recommendations. This is controversial, even in the US. You have iron-fortified first stage formula in the US - we don't have that here, because our experts do not think it is necessary, and because it may even be (according to some evidence) undesirable.
This is allowed, you know :) For experts to disagree, and to look at the evidence and come up with different public health recommendations, and most of all, to look at their own populations and guage what would be a sensible and practicable guideline.
To repeat: there is no case for routine iron supplementation of young babies in the UK. There is a case for routine vit d supplementation. Current public health guidance reflects this.