They do look like a typical I.a.alpestris. Judging by that slither of throat you can make out in the pic, it has no spotting, clarifying that it is not I.a.apunaus (Or I.a.inexpecatatus). The three main subspecies you can easily find in the UK is I.a.cyreni, I.a.apunaus and I.a.alpestris. We have already ruled out apunaus and it is more likely to be I.a.alpestris simply becase you do find them more then both other subspecies.