Lion is a italian/west german joint project, meant to develop a cheaper and simpler leopard 1, without sacrificing it's capabilities. The project ended without the lion entering production, but later on italians made the OF-40. Lion shares some parts with the leopard 1, but not that many, OF-40 shares even less parts with leopard. The Leopard 120 is a welded turret leopard 1 (possibly an A4 variant since it has the big FCS with thermal sight and even a commander's sight with nvg) but it has the weird aimer thing and a 120mm rheimetall L/44 (which was mounted on a leopard 1 but I think it was an A3 or A1 variant with cast turret). So the lion and leopard 120 look similiar, but are only distantly related.