I've brought two rainjackets, but only for real off season touring - like when I'm touring in November in the Northwest..... where I wanted both a riding raincoat and a camping raincoat.

Same strategy -all day riding raincoat was going to get soaked & I wanted a second raincoat along. Similar to having a totally separate set of dry clothing for winter camping.

Bringing a tarp to hang out under is a crucial key of dealing with wet weather camping.

For summer touring I avoid bringing two waterproof coats. Bringing a windbreaker like the J&G yellowjacket along with a bonifide raincoat is a great idea IMO. I wear a windjacket quite a bit while touring, they are also quite nice for sitting around camp as your nightime 'keep the heat in' shell layer...