Landman Previously Von Landmann

Believed (by oral history only) to have left Germany in 1860's with two brothers (names unk). Went to UK (Scotland?). Then they sailed away - one got off in Sth Africa; one in Australia, and my g/f to New Zealand. There are "LANDMAN / LANDMANN" names in all three countries. I have many "LANDMANs" in NZ, and tree going back to 1711 in Germany. I have no idea of linkages with South Africa or Australia, but have seen an ADOLF LANDMANN gravestone at Warrnambool in Vic, Sth Australia. Carl's sons went to war for NZ and fought against Germany! Thus the last "N" was dropped for anglicising.
Seeking ANY links, and happy to exchange information. There are MANY LANDMAN descendants in NZ: Carl was father to ten children.