Yes, I assumed that 'dwoje' should be used as they are 'groups', followed by the Genitive as in 'dwoje oczu i dwoje uszu'. It did not cross my mind that just because they were feminine they should not be classed as 'in groups'. In all my grammar notes in Numbering (a vast topic!) I have never seen this gender distinction when it came to groups/pairs. Could it be that because arms and legs are some distance apart from each other, they are not classed as being 'pairs/groups'? I remain a trifle mystified...
I'm not sure if it's worth going that deep, although it sure is interesting... Whatever the reason is, eyes and ears need the collective numeral, hands (arms) and legs may use it, but they usally take the normal feminine one.
Same in Russian. The collective dwoje, troje, cietwiero, etc. are only used for masculine personal nouns. dwoje mużcin, dwie żensiny "two men, two women"
Foot - stopa, feet - stopy, alloy - stop, alloys - stopy, stop - stop
hand - dłoń, hands - dłonie
Dwie dłonie i dwie stopy
Oh, interesting! Arms/legs and hands/feet are the same words in Russian, as weird as that is. Ruki/nogi. But the Russian word for the palm of your hand is ladoń which I'm sure is related to the Polish dłoń.