There is a difference between the Dutch Aleman and those, at least the most of them, Aleman everywhere else. The Dutch are descending from Willem III, who was a count of Holland and Henegouwen in the late 13th century. He had a bastard son whom he gave noble rights. He was called Jan Aelman (= Jan Adelman> adel=noble). The name developed in time to Aleman. Descendents could have emigrated all over the world and mix with those other Alemans. If you carry the name Aleman everywhere else in the world it is very well possible your anscestors came originally from Germany=Almania=Allemagne, so called after the Alamannen, a German clan. So, if your name is e.g. Dolores Aleman, you probably have nothing to do/nothing in common with e.g. Kommer Aleman from Ouddorp in the Netherlands.