I would think that you have a very good chance of getting shoulder weeks in those places........Aruba in May is one of the easiest months to get, and I love Aruba, in May. The weather is great, and no crowds. Just enough people around to make it fun.
Nov and March in Spain, are nice months, and not too difficult to get, Maybe even April.......BTW, with the current situation with the Caribbean, and Europe, your chances are much better than usual. Put in your request, right away, and go for it. You never know what might just show up in your account.