Juvenile Arctic Redpoll - where's the beef?

Hi,

after going on a recent expedition to Arctic Norway I was exposed to (what was unbeknownst to me) the Redpoll issue. Here in the UK I get the inkling  (ignore my generalising just an impression) that many folk are splitting these Redpoll into categories that don't really exist - I for one was one of them.

To begin with (I hope to write further posts on this subjective topic) I would like to give you a taster of what I mean. Could you enlighten me on the identification of this bird?

Before going to Norway and having to study each Redpoll as if it was a new species, I would instantly rule out Arctic (it's too brown we've been told all along)! I would then focus on Mealy and Lesser. Now I hope you noticed the bill; supposedly Mealy have the largest/longest bill; this clearly has a tiny one. So there you have it a Lesser Redpoll but wait hang on a sec we're 400 miles north of the Arctic Circle so geographically it CAN'T be a Lesser. It also has only 1 dark shaft in one of its under tail coverts and it has a white rump. Hang on then, what is this telling us? We've got a bird that is meant to have the longest bill of its family yet acquires the smallest one I have seen. Get where I'm going here? 

There you have it. This whole Redpoll malarkey is all gobbledygook - yes I know we all know that, which makes this so interesting. Let's not stop here, however and try to get to the end of this mysterious juvenile bird. For me structurally (and in a few places plumage wise) this instantly gave me an Arctic Redpoll impression. I'll run through the pros: small bill, rounded, tiny head, densely feather legs, white rump and only 1 dark tail shaft. Bearing this in mind I quickly went to the web in search of a photo and/or even better description of exilipes in juvenile plumage. What did I find? Nothing. What gets me is how we can describe this as a distinct species when there's no text describing them (at least to my knowledge)! 

What I keep getting the vibes of is this being the same situation as Chiffchaffs: clinal. Collybita-trisits, cabaret-exilipes. My fellow far more experienced ringers also discussed further that night (and throughout the holiday) about this bird and Redpolls, we all came to the same educated conclusion: lump them. Of course this isn't an exact science and we still are by no means definitive but I'll leave this question for you. To lump or not to lump? That is the question.