I tried to be a little more relaxed when knitting the second sleeve. My gauge turned out a little relaxed too. Sigh! The second sleeve is app 3½ cm longer than the first sleeve.
I decided to make the I-cord at the wrists and then try to block the hell out of it (excuse my language).
So far they look just about equal in size. Actually the small one (at the bottom) looks bigger than the big one! I hope it works so I don't have to make a third sleeve!!!