In this case, of course, it is the order of the tour: your home-Sanya, Hainan-Zhuhai-Guangzhou-Shenzhen-Xiamen-home. You can also start from Xiamen upside down. You like it yourself. These cities are basically connected by high-speed rail or urban rail. Maybe there is some trouble in Sanya-Zhuhai section. As for Guangzhou, three or four days is usually enough. Travel around the new and old axis, eat all kinds of snacks and feel the Cantonese morning tea in Guangzhou.