Why rulers of Malindi welcomed the Portuguese?

Naturally, people of Malindi are kind and welcoming, and it has been inscribed in their culture to be welcome. However, some sections of historians claim that the reason why rulers of Malindi welcomed the Portuguese is basically due to their rivalry with the people of Mombasa. Since the Portuguese was a new formidable European power, creating an alliance and friendship with them would come in handy during times of war.