I think the bird in pictures 3-4 can identified as Eurasian with confidence:
in juvenile Short-Toed with still growing and such a stubby bill like in this bird, the bill is often more strongly curved (I write normally, because I have not seen enough juvenile Treecreepers to be sure of variation). And the bill would be to short if fully developed for Short-Toed.
The Underparts are gleaming white even on the flanks
Please note, that this bird was taken in the range of the subspecies familiaris, which has greater and whiter spots on the upperparts. In the Challenge-Book by Martin Garner the map for this subspecies covers entire Poland, but Eurasian on the German/Polish boarder showed upperparts not different from birds I had seen elsewhere in Europe (brown upperparts with "normal" white spots without frosty appearance), but some showed striking gleaming white underparts. An integration zone is the be expected in subspecies. (For what its worth attach pictures of an Eurasian Treecreeper from Chojna/E-Poland to illustrate this point)
Rump seems to be contrasting brown (better for Eurosaian) but Im not sure about this: it seems somewhat unnatural to me, to much pronounced than my experience.
The forecrown seems to be spotted white (pro Eurasian), but the picture quality is not so good to exclude an photographic artefact or feather shafts.
The wingpattern is difficult to judge, as Nutcracker said with very fresh and therefore broad and white feathertips, but I dont see anything that speaks against Eurasian: broad white tips around primary tips, the right primary spacing for familiaris, alula pattern is spot on (but so variable).