I don't think the r's are silent, they just take 'em away and use 'em somewhere else. Like after a's. I always crack up when listening to BBC Mid-East reports mentioning the "Garzer Strip"
Comment on Re^2: My favorite silent English letter is:
The bête noire in this household over the years has always been the invisible, but sometimes rolled, R that results in "law and order" sounding like "laurrrrra ndoda". And since "ndoda" means "man" in several of the Nguni languages, it could be a valid name.