Those numbers seem exceptionally low and it seems unlikely Google would think these engineers worth paying a premium for if the rest of the industry apparently does not (i.e. if they're worth that much, they should have left to work somewhere else already).

Engineering seems widely undervalued as a profession in many asian locales (not in Beijing/Shanghai/Shenzhen though, but then you have to use air- and internet filters). I don't think they have any easy options if they want to stay in Taiwan.